Novel Cu₂O quantum dots coupled flower-like BiOBr for enhanced photocatalytic degradation of organic contaminant

A facile ultrasonic-assisted fabrication of nitrogen-doped carbon dots/BiOBr up-conversion nanocomposites for visible light photocatalytic enhancements

A highly efficient novel photocatalyst consisting of nitrogen-carbon dots (N-CDs) and three-dimensional (3D) hierarchical BiOBr was synthesized via a simple ultrasonic-assisted method and used for the degradation of hazardous dyes. Deposition of N-CDs onto the surface of BiOBr was confirmed through structure and composition characterizations. The N-CDs/BiOBr composites exhibited superior activity for organic contaminant degradation under visible light and the 1 wt% N-CDs/BiOBr composite showed the highest degradation rate, indicating that N-CDs/BiOBr composites have great potential for application in mitigating hazardous contaminants. The N-CDs played an important role in improving the photocatalytic performance, owing to the enhancement of up-converted photoluminescence behavior as well as the efficient separation of photogenerated charge carriers originating from the intimately contacted interface. A possible photocatalytic mechanism was proposed based on the experimental results.

Biomimetic synthesis of Ag3PO4-NPs/Cu-NWs with visible-light-enhanced photocatalytic activity for degradation of the antibiotic ciprofloxacin

Cu-NWs/Ag₃PO₄-NPs can be used as photocatalysts under visible light irradiation and have high photocatalytic performance for degradation of CPFX.

Porous BiOBr/Bi2MoO6 Heterostructures for Highly Selective Adsorption of Methylene Blue

Porous BiOBr/Bi2MoO6 (Br/Mo) heterostructures were designed and successfully fabricated, in which BiOBr nanoparticles were deposited on the surface of the secondary nanoplate of three-dimensional porous Bi2MoO6 architectures through a deposition-precipitation process. The as-prepared Br/Mo heterostructures were used as an adsorbent to remove methylene blue (MB) from aqueous solution. The batch adsorption results indicated that 50.0 wt % Br/Mo heterostructures show an enhanced adsorption capacity compared with pure Bi2MoO6 and BiOBr. The effects of initial solution, initial concentration, and contact time were systematically investigated. The optimum adsorbent amount and the pH value were determined to be 0.8 g L-1 and 2, respectively. Meanwhile, the experiments also revealed that porous Br/Mo heterostructures possess higher preferential adsorptivity for MB than that for methyl orange (MO-) and rhodamine B (RhB+). The dynamic experimental result indicated that the adsorption process conforms to the pseudo-second-order kinetic model. Weber's intraparticle diffusion model indicated that two steps took place during the adsorption process. Thermodynamic analysis results showed that the adsorption is a physisorption process, which conforms to the Langmuir isotherm model. Additionally, the possible adsorption mechanism was also investigated. The present study implied that Br/Mo heterostructures are promising candidates as adsorbents for MB removal. Therefore, fabrication of semiconductor-based heterostructures could be a strategy to design new efficient adsorbents for the removal of environmental pollutants.

La and F co-doped Bi2MoO6 architectures with enhanced photocatalytic performance via synergistic effect

Solvothermally-synthesized La and F co-doped Bi₂MoO₆ architectures showed significantly enhanced photocatalytic activities and the photocatalytic mechanism was proposed.

Hierarchical photocatalysts

The design, fabrication, performance and applications of hierarchical semiconductor photocatalysts are thoroughly reviewed and apprised.

A photocatalytic graphene quantum dots–Cu2O/bipolar membrane as a separator for water splitting

A novel graphene quantum dots–Cu₂O/bipolar membrane was used for water splitting with photoelectron-synergistic catalysis.

Fabrication and characterization of hollow CdMoO4 coupled g-C3N4 heterojunction with enhanced photocatalytic activity

This research was designed for the first time to investigate the activities of CdMoO4/g-C3N4 heterojunction in photocatalytic degradation of rhodamine B (RhB) and converting CO2 to fuels. The composite was synthesized via a simple mixing-calcination method and characterized by various techniques including Brunauer-Emmett-Teller method (BET), X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and electrochemical method. The results showed that the introduction of CdMoO4 to g-C3N4 exerted little effect on the property of light absorption, but resulted in an increase in the BET surface area, which was beneficial for the adsorption of RhB. More importantly, formation of a hetero-junction structure between CdMoO4 and g-C3N4 significantly promoted the separation of electron-hole pairs and ultimately enhanced the photocatalytic activity. The optimal CdMoO4/g-C3N4 composite could degrade RhB 6.5 times faster than pure g-C3N4 under visible light irradiation. Meanwhile, the composite showed a CO2 conversion rate of 25.8 μmol h(-1) gcat(-1), which was 4.8 and 8.1 times higher than those of g-C3N4 and P25, respectively, under simulated sunlight irradiation. This work might represent an important step in simultaneous environmental protection and energy production by g-C3N4 based materials.

Construction of amorphous TiO₂/BiOBr heterojunctions via facets coupling for enhanced photocatalytic activity

Facets coupled BiOBr with amorphous TiO2 composite photocatalysts are synthesized via an in situ direct growth approach under microwave irradiation. XRD, SEM and HRTEM characterizations indicate that the heterointerface between BiOBr and amorphous TiO2 occurs mainly on the {001} facets of BiOBr. BET and TEM verify that the heterojunctions possess higher specific surface areas and smaller amorphous TiO2 particle size than bare BiOBr and amorphous TiO2, exhibiting the inhibition function of BiOBr on the growth of TiO2 particles. XPS verifies the interaction between the two components. The degradation of methyl orange (MO) and phenol are used as the objective reaction to evaluate the photocatalytic activity of the as-prepared samples. The reaction rate constant of 15% TiO2/BiOBr composite is 3.4 times greater than that of pure BiOBr, which is attributed to its higher surface area, and efficient separation of photo-generated electron-hole pairs between BiOBr and amorphous TiO2.

Bi5 O7 I Nanobelts: Synthesis, Modification, and Photocatalytic Antifouling Activity

Bi5 O7 I nanobelts were prepared by a facile hydrothermal method to study the crystal phase transformation and morphology evolution. Based on these results, a crystal growth mechanism of Bi5 O7 I nanobelts was proposed. To enhance the photocatalytic antifouling activity, ethanol or TiCl3 was used to modify the Bi5 O7 I nanobelts. The resulting BiOI/Bi2 O2 CO3 /Bi5 O7 I and TiO2 /BiOCl/Bi5 O7 I micro-nanostructures show excellent degradation activity of malachite green and bactericidal effects against Pseudomonas aeruginosa, which may be attributed to the higher charge carrier separation efficiency of these heterojunction structures. The results indicate that the formation of semiconductor composites is a very effective strategy to design high-performance photocatalyst systems.

Simulated sunlight photocatalytic degradation of aqueous p-nitrophenol and bisphenol A in a Pt/BiOBr film-coated quartz fiber photoreactor

Pt/BiOBr film-coated quartz fiber bundles were prepared by dip-coating combined with photodeposition, and their phase and chemical structures, electronic and optical properties, textural properties as well as morphologies were well-characterized.

Improved photocatalytic activity of MoS2 nanosheets decorated with SnO2 nanoparticles

MoS₂ nanosheets decorated with SnO₂ mesoporous nanoparticles were successfully prepared by a facile two-step method.

Novel Cu2S quantum dots coupled flower-like BiOBr for efficient photocatalytic hydrogen production under visible light

The BiOBr act as excellent supporting materials to improve the dispersion of the Cu₂S QDs and the well-matched overlapping band-structures greatly accelerate the separation of photogenerated carriers.