Synergistic heterojunction effects in Ag3PO4/SnO2 nanocomposites: a photocatalytic study on isoproturon degradation

Introduction

Pesticides such as isoproturon are widely employed and represent a considerable environmental concern. The development of sustainable and efficient degrading techniques is crucial. Photocatalytic degradation employing semiconductor materials is a compelling solution. This study examines the synergistic advantages of heterojunction formation by synthesizing, characterizing, and improving the photocatalytic efficacy of Ag3PO4/SnO2 nanocomposites for the degradation of isoproturon.

Methods

The Ag3PO4/SnO2 nanocomposite was characterised using powder X-ray diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Ultraviolet-Diffuse Reflectance Spectroscopy (UV-DRS) and X-ray Photoelectron Spectroscopy (XPS). The effective synthesis of the Ag3PO4/SnO2 heterojunction was confirmed by characterization data from various techniques (PXRD, FTIR, SEM, UV-DRS, XPS).

Results and Discussion

Elemental mapping confirmed uniform distribution of O, P, Ag, and Sn. High-resolution mass spectrometry (HRMS) was employed to analyse degradation products. The Ag3PO4/SnO2 nanocomposite exhibited improved photocatalytic degradation of isoproturon compared to its precursors. In contrast to 25% for pure SnO2 and 41% for Ag3PO4, over 97% degradation was achieved using Ag3PO4/SnO2 nanocomposite within 120 min of light irradiation under identical conditions. The synergistic effects of heterojunction formation significantly enhanced isoproturon degradation using the Ag3PO4/SnO2 nanocomposite. The heterojunction reduces electron-hole recombination rate and enhances photogenerated charge carriers for degradation via effective charge separation. The improved photocatalytic activity is ascribed to the increased surface area of the nanocomposite. The analysis of HRMS data revealed the degradation products. The findings demonstrate the efficacy of Ag3PO4/SnO2 nanocomposites as photocatalysts for environmental remediation, namely in the breakdown of pesticides.

Superior Photocatalytic Activity of BaO@Ag3PO4 Nanocomposite for Dual Function Degradation of Methylene Blue and Hydrogen Production under Visible Light Irradiation

The current work focuses on the photo degradation of organic pollutants, particularly methylene blue (MB) dye, and the production of hydrogen as green energy using a composite of silver phosphate Ag3PO4 (AP) and barium oxide/silver phosphate BaO@Ag3PO4 (APB) as a photocatalyst. This composite was successfully synthesized using a chemical co-precipitation approach. The physicochemical properties of the obtained samples were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis/DRS), and photoluminescence (PL) spectrophotometry. From XRD, the average crystallite sizes of AP and APB are 39.1 and 46 nm, respectively, with a homogeneous morphology detected by SEM. UV and PL experiments showed that the compound is active under visible light, with an improvement in the lifetimes of the electrons and the holes in the presence of BaO with Ag3PO4. The as-synthesized APB photocatalyst sample showed a remarkably high degradation efficiency of MB (20 ppm, 50 mL) of around 94%, with a hydrogen production yield of around 7538 μmol/(h·g), after 120 min of illumination, which is greater than the degradation efficiency of the AP photocatalyst sample, which was about 88%. The high photodegradation efficiency was attributed to the electronic promotion effect of the BaO particles. The APB composite demonstrated an increased photocatalytic performance in effectively degrading an organic dye (MB) with no secondary pollutants when exposed to visible light irradiation.

High-Efficient Visible-Light Photocatalysis Performance and Light-Corrosion Resistance of Ag3PO4 Constructed by double-Z System Composites

Novel visible-light-driven Ag₃PO₄/AgBr/AgI photocatalysts were prepared via a simple self-assembly strategy combined with in-situ anion-exchanging process. The photocatalytic activity of Ag₃PO₄ was significantly improved by constructing double-Z system. Specifically, the obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (DRS). Under visible light irradiation (λ > 420 nm), the Ag₃PO₄/AgBr/AgI photocatalysts showed much higher photocatalytic activity than bulk Ag₃PO₄ for the degradation of formaldehyde (HCHO), and 100% HCHO degradation could be obtained within 28 min. The degradation efficiency could be maintained in five cycles. Further electron paramagnetic resonance (ESR) tests demonstrated that both •OH and •O₂^- generated in the system. This study provides new insights into the fabrication of highly efficient visible-light-driven photocatalysts and facilitates their practical application in emerging environment issues.

Porous hollow Ag/Ag2S/Ag3PO4 nanocomposites as highly efficient heterojunction photocatalysts for the removal of antibiotics under simulated sunlight irradiation

Antibiotic pollutants are a serious and growing threat to human health and the environment that efficient measures must be taken to eliminate them. Here, we report the facile fabrication of porous hollow Ag/Ag₂S/Ag₃PO₄ heterostrucutres for efficient photocatalytic degradation of tetracycline under simulated sunlight irradiation. The morphology manipulation and hetero-nanocomposites construction through a coprecipitation-refluxing approach were applied to enhance the photocatalytic performance of the Ag/Ag₂S/Ag₃PO₄ products. The photodegradation outcomes indicated that the heterojunction Ag/Ag₂S/Ag₃PO₄ photocatalyst with a suitable band gap energy of 2.17 eV, has better degradation performance (∼95%) than individual Ag₂S and Ag₃PO₄ structures after 120 min of simulated sunlight irradiation, even after five recycles. The good photocatalytic activity of Ag/Ag₂S/Ag₃PO₄ nanocomposites could be mainly attributed to the unique hierarchical architectures, promoted visible-light harvesting, reduced a recombination and boosted separation of electron-hole pairs originated from the as-formed heterojunctions. Moreover, we proposed a photocatalytic degradation mechanism based on the radical scavenging results, which disclosed that the ^•O₂^- and ^•OH species perform essential tasks for the photodegradation of antibiotics by Ag/Ag₂S/Ag₃PO₄ nanocomposites.

The application of FTO-Cu2O/Ag3PO4 heterojunction in the photoelectrochemical degradation of emerging pharmaceutical pollutant under visible light irradiation

We report the photoelectrochemical application of a visible light active FTO-Cu₂O/Ag₃PO₄ photoanode for the abatement of sulfamethoxazole in water. The as-synthesised photoanodes were characterised using XRD, field emission SEM, EDX, diffuse reflectance UV-vis, impedance spectroscopy and chronoamperometry. The results obtained confirmed a successful formation of p-n heterojunction at the Cu₂O/Ag₃PO₄ interface. The highest photocurrent response of 0.62 mAcm^-2 was obtained for the composite photoanode which was four times higher than pure Cu₂O and about three times higher than pristine Ag₃PO₄. The photoanode gave 67% removal efficiency within 2 h upon its photoelectrochemical application in the degradation of sulfamethoxazole with 1.5 V bias potential at pH 6.2. The FTO-Cu₂O/Ag₃PO₄ electrode was also applied in the treatment of a cocktail of synthetic organics containing sulfamethoxazole and orange II dye. The photogenerated holes was found to be the major oxidant and the photoanodes was stable and reusable.

Synthesis of TiO2–Ag3PO4 photocatalyst material with high adsorption capacity and photocatalytic activity: application in the removal of dyes and pesticides

The photocatalytic activity of TiO₂ can be enhanced by coupling it with other semiconductors and the semiconductor composites may find useful application in water treatment technologies. TiO₂–Ag₃PO₄ composites were synthesized and characterized with XRD, SEM-EDX and DRS. The synthesized TiO₂–Ag₃PO₄ showed high photocatalytic activity in the presence UV-vis light on rhodamine B, methylene blue and the pesticides imidacloprid, atrazine and pyrimethanil. LC-MS analysis of the photodegraded pyrimethanil led to the identification of hydroxylated and aliphatic derivatives of pyrimethanil. The photocatalytic activity of the coupled semiconductor was higher than that of the bare TiO₂ and Ag₃PO₄ and this was attributed to the unique band matching between TiO₂ and Ag₃PO₄ which resulted in efficient charge separation and subsequent reduction in the electron–hole recombination. In addition, the synthesized TiO₂–Ag₃PO₄ showed strong adsorption for water soluble dyes implying that TiO₂–Ag₃PO₄ can remove pollutants through photocatalysis and adsorption. The results from the study showed the potential application of TiO₂–Ag₃PO₄ composite in water treatment technologies.

Synthesis scheme of the Ag₃PO₄–TiO₂ nanocomposite.

Electrospun Active Media Based on Polyvinylidene Fluoride (PVDF)-Graphene-TiO2 Nanocomposite Materials for Methanol and Acetaldehyde Gas-Phase Abatement

The abatement of organic pollutants by TiO2 photocatalysis has been established as one of the benchmark applications of advanced oxidation processes for both liquid and gas phase purification. Such solution is particularly suitable for indoor air pollution where volatile organic compounds (VOCs) represent a class of chemicals of high concern for their adverse effects on both environment and human health. However, different shortcomings still affects TiO2 photocatalytic performance in terms of weak adsorptivity and fast electron-hole recombination, limiting its applicability. As a result, different strategies have been investigated over the last years in order to promote a higher TiO2 photo-efficiency. In this study we used electrospun (PVDF) nanofibers as a support for the photo catalytic system obtained by coupling graphene based materials and TiO2 during solvothermal synthesis. The resultant nanostructured membranes have been tested for acetaldehyde and methanol degradation under UV light showing an increase in the photocatalytic activity compared to bare TiO2. Such results may be ascribed to the decrease of band-gap energy and to increased electron mobility in the photocatalytic nanocomposite.

Agro-waste extracted cellulose supported silver phosphate nanostructures as a green photocatalyst for improved photodegradation of RhB dye and industrial fertilizer effluents

The efficiency and reusability of photocatalysts are the dominant factors for their pragmatic use. The visible light induced semiconductor silver phosphate is a superior photocatalyst effective under visible light but its stability is still an undiscussed issue. To overcome this stability issue in this present manuscript, eco-friendly agro-waste extracted cellulose supported silver phosphate nanostructures have been designed for the first time through a simple chemical process. At first, silver phosphate nanostructures were synthesized by the co-precipitation method. Then, different weights of cellulose were added to the silver nitrate solution to form cellulose supported silver phosphate nanostructures. The photodegradation efficiency for each weight ratio was examined in which the photocatalyst Ag-8 nanostructures showed a high rate (0.024 min^-1) for degradation of Rhodamine B (RhB) using a low intensity tungsten bulb. Real sample analysis has also been carried out using this photocatalyst for the degradation of industrial fertilizer effluents. The degradation rate of all the nanostructures was found to be high in comparison to pristine silver phosphate as well as the extracted bare cellulose. The photocatalytic activity is enhanced because of the participation of cellulose as a support which makes an interface for silver phosphate and assists it in delaying the charge recombination period under visible light. To understand the photochemical reaction of electrons and holes, scavenger studies were also performed.

Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

In this study, the Ag3PO4/SnO2 heterojunction on carbon cloth (Ag3PO4/SnO2/CC) was successfully fabricated via a facile two-step process. The results showed that the Ag3PO4/SnO2/CC heterojunction exhibited a remarkable photocatalytic performance for the degradation of Rhodamine B (RhB) and methylene blue (MB), under visible light irradiation. The calculated k values for the degradation of RhB and MB over Ag3PO4/SnO2/CC are 0.04716 min−1 and 0.04916 min−1, which are higher than those calculated for the reactions over Ag3PO4/SnO2, Ag3PO4/CC and SnO2/CC, respectively. The enhanced photocatalytic activity could mainly be attributed to the improved separation efficiency of photogenerated electron-hole pairs, after the formation of the Ag3PO4/SnO2/CC heterojunction. Moreover, carbon cloth with a large specific surface area and excellent conductivity was used as the substrate, which helped to increase the contact area of dye solution with photocatalysts and the rapid transfer of photogenerated electrons. Notably, when compared with the powder catalyst, the catalysts supported on carbon cloth are easier to quickly recycle from the pollutant solution, thereby reducing the probability of recontamination.

Dual-functional Ag3PO4@palygorskite composite for efficient photodegradation of alkane by in situ forming Pickering emulsion photocatalytic system

Removal of oil from water is highly imperative, because of the worldwide oil-contaminated water caused by industrial development and oil spill accidents. As a solution to meet the demand for clean energy technology, photocatalysis has drawn great attention recently. However, a major problem encountered in photodegrading oil is the difficult availability of oil by photocatalyst. To overcome this problem, a novel concept of integrating Pickering emulsification of palygorskite (PAL) clay particles with photocatalytic activity of Ag₃PO₄ is proposed in this work. By a simple co-precipitation method, Ag₃PO₄@PAL composite was prepared and used for the simultaneous emulsification and decomposition of tetradecane. Via a simple Pickering emulsion-based photocatalytic system, Ag₃PO₄ could contact with tetradecane directly, which effectively overcomes the agglomeration and settlement of Ag₃PO₄ in aqueous phase. This in situ photocatalytic system shows a higher efficiency for photodegradation of tetradecane, comparing with traditional solution-dispersed photocatalytic system. Under visible-light irradiation, the removal efficiency of tetradecane is 4.9 times higher than Ag₃PO₄ alone. Direct contact of Ag₃PO₄ with oil pollutes and sufficiently large active surface area greatly improve the efficiency of photodegrading oil. This study provides a new and simple strategy for oil photodegradation via an in situ Pickering emulsion system.

Superior decontamination of toxic organic pollutants under solar light by reduced graphene oxide incorporated tetrapods-like Ag3PO4/MnFe2O4 hierarchical composites

To fabricate an efficient, eco-friendly and stable photocatalyst, the current work describes a demonstration of simple synthesis approach of Ag₃PO₄/MnFe₂O₄(x wt%)/reduced graphene oxide composites. Ag₃PO₄/MnFe₂O₄ (5 wt%) revealed superior activity for decontamination of dye pollutant. Further, rGO was incorporated with Ag₃PO₄/MnFe₂O₄ (5 wt%) to investigate its effect on their overall properties. The resultant composites were characterized by various analytical techniques to confirm their structural and physical-chemical features. FESEM analysis showed that morphology of Ag₃PO₄ varied significantly from orthorhombic dodecahedrons to tripods and tetrapods with the combinations MnFe₂O₄ (5 wt%), and MnFe₂O₄ (5 wt%)+rGO respectively. The photocatalytic decontamination of toxic organic dyes tested against Rhodamine B(RhB) and 4-Nitrophenol. The outstanding performance for decontamination of RhB was observed for Ag₃PO₄/MnFe₂O₄(5 wt%)/rGO (~99% in 5 min) with the rate of k = 7.28 × 10^-1 min^-1. The enhanced activity of Ag₃PO₄/MnFe₂O₄(5 wt%)/rGO composites credited to co-catalytic effects of MnFe₂O₄ and physiochemical properties of rGO which leads to making intimate contact with Ag₃PO₄ to form heterojunction and rGO served as a medium for charge transfer to prevent their recombination. The incorporation of rGO in Ag₃PO₄/MnFe₂O₄ (5 wt%) composite leads to a considerable increase in the photocatalytic activity by offering improved surface area and properties, high electron stability and mobility. Based on experiment results, the photocatalytic enhancement mechanism for organic pollutants degradation was discussed. The recyclability of Ag₃PO₄/MnFe₂O₄(5 wt%)/rGO hierarchical composite was evaluated by replicated photocatalytic reaction trials. Overall, the morphological transformation of Ag₃PO₄/MnFe₂O₄(5 wt%)/rGO composites played a dynamic role in determining their photocatalytic activity towards the organic industrial dye pollutants.

Rational design direct Z-scheme BiOBr/g-C3N4 heterojunction with enhanced visible photocatalytic activity for organic pollutants elimination

A rapid recombination of photo-generated electrons and holes, as well as a narrow visible light adsorption range are two intrinsic defects in graphitic carbon nitride (g-C3N4)-based photocatalysts. Inspired by natural photosynthesis, an artificially synthesized Z-scheme photocatalyst can efficaciously restrain the recombination of photogenerated electron-hole pairs and enhance the photoabsorption ability. Hence, to figure out the above problems, BiOBr/g-C3N4 composite photocatalysts with different mass ratios of BiOBr were successfully synthesized via a facile template-assisted hydrothermal method which enabled the BiOBr microspheres to in situ grow on the surface of g-C3N4 flakes. Furthermore, to explore the origin of the enhanced photocatalytic activity of BiOBr/g-C3N4 composites, the microstructure, photoabsorption ability and electrochemical property of BiOBr/g-C3N4 composites were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS) and photocurrent (PC) response measurements. As a result, the introduction of BiOBr on g-C3N4 to constitute a direct Z-scheme heterojunction system can effectively broaden the light absorption range and promote the separation of photo-generated electron-hole pairs. Hence, compared with pure g-C3N4 and BiOBr, the resultant BiOBr/g-C3N4 composites exhibit the remarkable activity of photodegradated rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) under visible light irradiation. Simultaneously, the optimal BiOBr content of the BiOBr/g-C3N4 composites was obtained. The BiOBr/g-C3N4 composites exhibit an excellent photostability and reusability after four recycling runs for degradation RhB. Moreover, the active-group-trapping experiment confirmed that ·OH, ·O2 - and h+ were the primary active groups in the degradation process. Based on the above research results, a rational direct Z-scheme heterojunction system is contrastively analyzed and proposed to account for the photocatalytic degradation process of BiOBr/g-C3N4 composites.

Low-temperature H2S gas sensor based on spherical Ag3PO4-doped SnO2

An efficient method for detecting H₂S gas at low temperatures using micrometer-sized spherical Ag₃PO₄-doped SnO₂materials synthesized by hydrothermal and chemical precipitation methods is reported.

Tetrahedral UMOFNs/Ag3PO4 Core-Shell Photocatalysts for Enhanced Photocatalytic Activity under Visible Light

A new visible-light-responsive tetrahedral ultrathin metal-organic framework nanosheet (UMOFNs)/Ag₃PO₄ composite photocatalyst with a core-shell structure was readily synthesized by sonication in an organic solvent. Characterization methods for the photocatalyst included X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, and UV-vis diffuse reflectance spectroscopy. The XRD patterns of the composite photocatalyst before and after visible-light irradiation demonstrated that trace amounts of Ag ions in the composite photocatalyst easily transformed into Ag nanoparticles, which play a role in promoting charge separation at the interface of a heterojunction. The UMOFNs/Ag₃PO₄ composite photocatalyst showed higher photocatalytic activity for the photodegradation of 2-chlorophenol (2-CP) under visible-light irradiation (>420 nm) than Ag₃PO₄. The complete degradation of 2-CP was achieved in 7 min using the tetrahedral UMOFNs/Ag₃PO₄ core-shell photocatalyst, and the apparent reaction rate was approximately 26 times higher than that of pure Ag₃PO₄. Further, a scavenger experiment showed h⁺ and O₂ ^•- were the major reactive species involved in the photocatalytic reaction system. This enhanced photocatalytic activity results from the efficient separation of photoinduced electron-hole pairs and the increase of interface area between Ag₃PO₄, UMOFNs, and the Ag nanoparticles.

Ag3PO4 Deposited on CuBi2O4 to Construct Z-Scheme Photocatalyst with Excellent Visible-Light Catalytic Performance Toward the Degradation of Diclofenac Sodium

CuBi₂O₄/Ag₃PO₄ was synthesized through a combination of hydrothermal synthesis and an in situ deposition method with sodium stearate as additives, and their textures were characterized with XRD, XPS, SEM/HRTEM, EDS, UV-Vis, and PL. Then, the photodegradation performance of CuBi₂O₄/Ag₃PO₄ toward the degradation of diclofenac sodium (DS) was investigated, and the results indicate that the degradation rate of DS in a CuBi₂O₄/Ag₃PO₄ (1:1) system is 0.0143 min⁻¹, which is 3.6 times that in the blank irradiation system. Finally, the photocatalytic mechanism of CuBi₂O₄/Ag₃PO₄ was discussed, which follows the Z-Scheme theory, and the performance enhancement of CuBi₂O₄/Ag₃PO₄ was attributed to the improved separation efficiency of photogenerated electron–hole pairs.

New approach for the transformation of metallic waste into nanostructured Fe3O4 and SnO2-Fe3O4 heterostructure and their application in treatment of organic pollutant

Appropriate recycling of waste to reusable materials is much sought after in the scientific community to control the incessant rising pollution in environment due to insufficient management of waste materials. To address this issue, efforts were directed to obtain SnO₂-Fe₃O₄ nanocomposites from scrap tin plated steel and the use of these composites for the degradation of organic pollutant. We have demonstrated a novel, efficient and facile hydrometallurgy approach for the extraction of iron from waste tin plated steel containers found in plenty in the common waste generated in society. The extracted iron has further been utilized for the preparation of SnO₂:Fe₃O₄ nanocomposites with different compositions (SnO₂:Fe₃O₄ ratio of 93.2:6.8, 85:15, 58:42 and 40:60) using hydrothermal route. The photocatalytic activities of nanocomposite were determined spectroscopically using Rhodamine-B (RhB) as a model dye. Our results indicate that among all the composites with SnO₂ (85%):Fe₃O₄ (15%) exhibits the best photocatalytic efficiency under UV light whereas the composition of SnO₂ (93.2%):Fe₃O₄ (6.28%) is the most efficient in visible light. The above visible light efficiency was supported by density functional theory (DFT) studies which suggest a small amount of pure Fe is present at the Sn sites in the nanocomposite, leading to the reduction in the band gap of the nanocomposite and resulting in absorption in the visible range. Thus, in the present study, we have shown a process of conversion of waste to nanomaterials and its utilization for treatment of organic pollutants.

A green approach for the synthesis of novel Ag3PO4/SnO2/porcine bone and its exploitation as a catalyst in the photodegradation of lignosulfonate into alkyl acids

A novel Ag3PO4/SnO2/porcine bone composite photocatalyst was successfully prepared via an ion exchange method, which can convert lignin derivatives into small molecular acids upon exposure to visible light at room temperature at ambient pressure. The composition characterization, optical absorption properties and photocatalytic activities of the Ag3PO4/SnO2/porcine bone composites were thoroughly investigated. The certain role of each component of the composites in the degradation reaction was discussed: Ag3PO4 acted as the major active component, while SnO2 and porcine bone as cocatalyst contributed to improve the photocatalytic activity and stability of Ag3PO4. The enhanced activity of the Ag3PO4/SnO2/porcine bone composite may be attributed to the synergistic effect including the matched energy band structures of Ag3PO4 and SnO2 for the decrease in the probability of electron-hole recombination and improved performance in the presence of hierarchical porous porcine bone (hydroxyapatite). This paper also analyzed the change of the molecular weight and structure of sodium lignin sulfonate in the photocatalytic reaction and discussed the possible photocatalytic mechanism of the photocatalyst composite, indicating that the benzene rings of guaiacol were oxidized into different alkyl acids (maleic acid, oxalic acid, formic acid and methoxy acetic acid).

Fabrication of RuO2-Ag3PO4 heterostructure nanocomposites: Investigations of band alignment on the enhanced visible light photocatalytic activity

The RuO₂-Ag₃PO₄ heterostructured nanocomposite was successfully synthesized by facile in situ deposition of porous ruthenium oxide (RuO₂) nanoparticles on the surface of the silver phosphate (Ag₃PO₄). Under visible light irradiation, the 0.5wt.% RuO₂-Ag₃PO₄ heterostructure photocatalyst exhibits enhanced photocatalytic efficiency compared to other composites of RuO₂-Ag₃PO₄ and Ag₃PO₄. The optimized 0.5wt.% RuO₂-Ag₃PO₄ nanocomposites exhibited 1.5 times enhanced photocatalytic activity towards the degradation of methylene blue (MB) than Ag₃PO₄. Moreover, the degradation rate of 0.5wt.% RuO₂-Ag₃PO₄ nanocomposite towards the cationic dyes MB and rhodamine B (RhB) was nearly 6.6 times and 4.7 times higher than that towards the anionic dye methyl orange (MO). The formed heterojunction electric field of 310mV at the interface between RuO₂ and Ag₃PO₄ heterostructure induces downward band bending of Ag₃PO₄. Also, this electric field increases the separation efficiency of electrons-holes resulting higher degradation efficiency. The quenching effect of scavengers test confirms that holes are reactive species and the RuO₂-Ag₃PO₄ nanocomposite is highly stable, exhibited 88% of MB degradation after 4 recycles. The RuO₂-Ag₃PO₄ nanocomposites inhibit self oxidation of Ag₃PO₄ resulting improved efficiency and stability.

Synthesis of silver phosphate/graphene oxide composite and its enhanced visible light photocatalytic mechanism and degradation pathways of tetrabromobisphenol A

In the present study, silver phosphate/graphene oxide (Ag₃PO₄/GO) composite was synthesized by ultrasound-precipitation processes. Afterwards, physicochemical properties of the resulting samples were studied through scanning electron microscope, transmission electron microscope, X-ray diffraction, N₂ adsorption/desorption, UV-vis diffuse reflectance spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, surface photovoltage spectroscopy and photoelectrochemical measurements. Results indicated that spherical Ag₃PO₄ displayed an average diameter of 150 nm and body-centered cubic crystal phase, which was integrated with GO. In addition, the visible light absorbance, charge separation efficiency and lifetime of Ag₃PO₄ were significantly improved by integration with GO. In addition, Ag₃PO₄/GO composite was applied to decompose tetrabromosphenol A (TBBPA) in water body. It was found that TBBPA could be completely decomposed within 60 min illumination. Furthermore, several scavenger experiments were conducted to distinguish the contribution of reactive species to the photoctalytic efficiency. Moreover, the enhanced visible light mechanism of Ag₃PO₄/GO was proposed and discussed. Eventually, several PC decomposition pathways of TBBPA were identified including directly debromination and oxidation, and subsequently further oxidation and hydroxylation processes.

A novel Bi4Ti3O12/Ag3PO4 heterojunction photocatalyst with enhanced photocatalytic performance

In this work, we integrated Ag₃PO₄ with Bi₄Ti₃O₁₂ to form Bi₄Ti₃O₁₂/Ag₃PO₄ heterojunction nanocomposites by an ion-exchange method. The as-prepared Bi₄Ti₃O₁₂/Ag₃PO₄ composites were systematically characterized by means of XRD, SEM, TEM, BET, XPS, UV-vis DRS, EIS, PL spectroscopy, and photocurrent response. SEM, TEM, and XPS results demonstrate the creation of Bi₄Ti₃O₁₂/Ag₃PO₄ heterojunction with obvious interfacial interaction between Bi₄Ti₃O₁₂ and Ag₃PO₄. PL spectra, EIS spectra, and photocurrent responses reveal that the composites display an enhanced separation efficiency of photogenerated electron-hole pairs, which is due to the charge transfer between Bi₄Ti₃O₁₂ and Ag₃PO₄. Rhodamine B (RhB) was chosen as the target organic pollutant to evaluate its degradation behavior over Bi₄Ti₃O₁₂/Ag₃PO₄ composites under simulated sunlight irradiation. Compared to bare Bi₄Ti₃O₁₂ and Ag₃PO₄ nanoparticles, the composites exhibit a significantly enhanced photocatalytic activity. The highest photocatalytic activity is observed for the 10% Bi₄Ti₃O₁₂/Ag₃PO₄ composite with 10% Bi₄Ti₃O₁₂ content, which is about 2.6 times higher than that of bare Ag₃PO₄. The photocatalytic mechanism involved was investigated and discussed in detail.

Fabrication of novel g-C3N4 nanocrystals decorated Ag3PO4 hybrids: Enhanced charge separation and excellent visible-light driven photocatalytic activity

Graphitic carbon nitride (g-C₃N₄) nanocrystals (NCs) decorated Ag₃PO₄ hybrids were synthesized by a facile method. The obtained samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), and UV-vis diffuse reflectance spectra (DRS). The SEM and TEM images showed that the as-prepared Ag₃PO₄ were composed of particles with diameters of 200-500nm, while the obtained nanocrystalline g-C₃N₄ were composed of smaller particles with average diameter of 10nm. For nanocrystalline g-C₃N₄/Ag₃PO₄ hybrids, the particle surfaces of Ag₃PO₄ were decorated with numerous g-C₃N₄ NCs, result in a larger contact area between g-C₃N₄ and Ag₃PO₄. The photocatalytic performances were evaluated by decomposing MO, phenol, bisphenol A, and RhB under visible light. Compared with Ag₃PO₄ and g-C₃N₄, the g-C₃N₄/Ag₃PO₄ hybrid (mass ratio=1:4) exhibited the best activity, which was much higher than that of bulk-g-C₃N₄/Ag₃PO₄ composite under the same conditions. The enhanced activities should be mainly ascribed to the enhanced separation efficiency of photo-generated carriers, which was proved by the photoluminescence (PL) spectra measurement. Controlled experiments proved that O₂^- and h⁺ played the chief role in the degradation process. A possible Z-scheme degradation mechanism of organic contaminant over g-C₃N₄/Ag₃PO₄ hybrid was proposed.

Ag3PO4/CoFe2O4 magnetic nanocomposite: synthesis, characterization and applications in catalytic reduction of nitrophenols and sunlight-assisted photocatalytic degradation of organic dye pollutants

A novel magnetically recyclable Ag₃PO₄/CoFe₂O₄ nanocomposite was synthesized by a facile hydrothermal method and its photocatalytic/catalytic performance for the degradation of organic dyes or reduction of nitro compounds was investigated.

A novel ternary CuO decorated Ag3AsO4/GO hybrid as a Z-scheme photocatalyst for enhanced degradation of phenol under visible light

A novel Z-scheme ternary CuO/Ag₃AsO₄/GO hybrid having significant visible light catalytic activity and stability is successfully synthesized via a self-assembly method.

Controlled synthesis of Sn-based oxides via a hydrothermal method and their visible light photocatalytic performances

Controlled synthesize of Sn-oxides was achieved via a facile hydrothermal method with SnCl₂ as precursor. A visible light photocatalytic activity of SnO₂ can be induced by doping with Sn²⁺ or coupling with SnO.

Electron transportation path build for superior photoelectrochemical performance of Ag3PO4/TiO2

An efficient electron transportation path built through preparing Ag₃PO₄/TiO₂ heterojunction by dipping method. It has a higher photocurrent density of 2.34 mA cm⁻².

In situ strategy to prepare PDPB/SnO2 p–n heterojunction with a high photocatalytic activity

PDPB/SnO₂ heterojunction has been successfully synthesized by an in situ growth strategy, which displays a narrowed bandgap, enhanced solar light absorption, excellent charge separation and improved solar-driven photodegradation rate of Rhodamine B.

Growth study of hierarchical Ag3PO4/LaCO3OH heterostructures and their efficient photocatalytic activity for RhB degradation

We demonstrate a simple, cost effective co-precipitation method to synthesize APO/LCO heterostructures and investigate the effect of a mixed solvent system (H₂O:THF) on the growth of microstructures.

Significant visible-light photocatalytic enhancement in Rhodamine B degradation of silver orthophosphate via the hybridization of N-doped graphene and poly(3-hexylthiophene)

Organic pollutants as typical water contaminants are potentially harmful to human health. In this study, we suggested that the novel Ag3PO4/N-doped graphene (NG)/Poly(3-hexylthiophene) (P3HT) composites can remove the organic dye Rhodamine B (RhB) from water. This Ag3PO4-based photocatalyst was synthesized via a facile method and subsequently characterized by XRD, SEM, TEM, XPS, Raman spectroscopy, PL spectroscopy, and UV-vis DRS. The photocatalytic activity of Ag3PO4/NG/P3HT composites is significantly higher than that of pristine Ag3PO4, Ag3PO4/NG, and Ag3PO4/P3HT for RhB degradation under visible light irradiation, especially the kinetic constant of Ag3PO4/NG/P3HT is more than 6 times of pristine Ag3PO4. The reactive oxygen species trapping experiments indicate that the degradation of RhB over the Ag3PO4/NG/P3HT composites mainly results from the holes oxidation and superoxide radical reduction. Besides, Ag3PO4/NG/P3HT composites exhibit better recyclability and stability than pristine Ag3PO4. Furthermore, the photocatalytic mechanism of Ag3PO4/NG/P3HT composites for RhB degradation under visible light was proposed as the synergistic effect of irradiated Ag3PO4, P3HT and NG sheets on the effective separation of photogenerated electron-hole pairs, and the enhancement of visible light absorbance.