Hydrothermal Co-Crystallization of Novel Copper Tungstate-Strontium Titanate Crystal Composite for Enhanced Photocatalytic Activity and Increased Electron–Hole Recombination Time

The development of catalysts continues to have a significant influence on science today since we can utilize them to efficiently destroy some contaminants. A study in this field is justified because there is a dearth of comprehensive literature on the creation of SrTiO3-based photocatalysts. Related to this topic, here we report the facile preparation of a structure-modified SrTiO3 photocatalyst, by incorporating CuWO4. Within the case of the CuWO4-modified samples (0.5–3 wt% nominal CuWO4 content), the photo-oxidation of phenol, as a contaminant, was more than two times higher than the initial SrTiO3. However, the photocatalytic activity does not change linearly with increasing CuWO4 content, and the CWS2.5 (2.5 wt% nominal CuWO4 content and 4.25 wt% measured content) has the highest photo-activity under the applied conditions. The reason for the better activity was the increased recombination time of charge separation on the catalyst surface. Slower recombination can result in more water being oxidized to hydroxyl radicals, leading to the faster decomposition of the phenol.

Boosted spatial charge carrier separation of binary ZnFe2O4/S-g-C3N4 heterojunction for visible-light-driven photocatalytic activity and antimicrobial performance

A potential method for removing toxins from contaminated wastewater, especially organic pollutants, is photo-catalysis. Here, a simple technique for producing zinc ferrite nanoparticles (ZnFe2O4 NPS) with varying quantities of sulphur doped graphitic carbon nitride nanocomposites (ZnFe2O4/S-g-C3N4 NCs) has been described. Then, using X-ray diffraction (XRD), TEM, EDX, XPS, photocurrent response, EIS, and Fourier Transform Infrared spectroscopy (FT-IR), the photo-catalytic activity of the produced nanoparticles (NPs) and nanocomposites (NCs) was examined and evaluated. The photo-catalytic activity of ZnFe2O4/S-g-C3N4 NCs was compared to a model pollutant dye, methylene blue, while degradation was evaluated spectrophotometrically (MB). Solar light has been used through irradiation as a source of lighting. The photocatalytic behaviour of the ZnFe2O4/S-g-C3N4 NCs photocatalyst was superior to that of genuine ZnFe2O4 and S-g-C3N4, which was attributed to synergic effects at the ZnFe2O4/S-g-C3N4 interconnection. Antimicrobial activity of ZnFe2O4/S-g-C3N4 against Gram-positive and Gram-negative bacteria under visible light was performed. In addition, these ZnFe2O4/S-g-C3N4 NCs show a lot of promise as an antibacterial agent.

Bioremediation of micropollutants using living and non-living algae - Current perspectives and challenges

The emergence and continual accumulation of industrial micropollutants such as dyes, heavy metals, organic matters, and pharmaceutical active compounds (PhACs) in the ecosystem pose an alarming hazard to human health and the general wellbeing of global flora and fauna. To offer eco-friendly solutions, living and non-living algae have lately been identified and broadly practiced as promising agents in the bioremediation of micropollutants. The approach is promoted by recent findings seeing better removal performance, higher efficiency, surface area, and binding affinity of algae in various remediation events compared to bacteria and fungi. To give a proper and significant insight into this technology, this paper comprehensively reviews its current applications, removal mechanisms, comparative efficacies, as well as future outlooks and recommendations. In conducting the review, the secondary data of micropollutants removal have been gathered from numerous sources, from which their removal performances are analyzed and presented in terms of strengths, weaknesses, opportunities, and threats (SWOT), to specifically examine their suitability for selected micropollutants remediation. Based on kinetic, isotherm, thermodynamic, and SWOT analysis, non-living algae are generally more suitable for dyes and heavy metals removal, meanwhile living algae are appropriate for removal of organic matters and PhACs. Moreover, parametric effects on micropollutants removal are evaluated, highlighting that pH is critical for biodegradation activity. For selective pollutants, living and non-living algae show recommendable prospects as agents for the efficient cleaning of industrial wastewaters while awaiting further supporting discoveries in encouraging technology assurance and extensive applications.

C-,N- and S-Doped TiO2 Photocatalysts: A Review

This article presents an overview of the reports on the doping of TiO2 with carbon, nitrogen, and sulfur, including single, co-, and tri-doping. A comparison of the properties of the photocatalysts synthesized from various precursors of TiO2 and C, N, or S dopants is summarized. Selected methods of synthesis of the non-metal doped TiO2 are also described. Furthermore, the influence of the preparation conditions on the doping mode (interstitial or substitutional) with reference to various types of the modified TiO2 is summarized. The mechanisms of photocatalysis for the different modes of the non-metal doping are also discussed. Moreover, selected applications of the non-metal doped TiO2 photocatalysts are shown, including the removal of organic compounds from water/wastewater, air purification, production of hydrogen, lithium storage, inactivation of bacteria, or carbon dioxide reduction.

N–TiO2 Photocatalysts: A Review of Their Characteristics and Capacity for Emerging Contaminants Removal

Titanium dioxide is the most used photocatalyst in wastewater treatment; its semiconductor capacity allows the indirect production of reactive oxidative species. The main drawback of the application of TiO2 is related to its high band-gap energy. The nonmetal that is most often used as the doping element is nitrogen, which is due to its capacity to reduce the band-gap energy at low preparation costs. There are multiple and assorted methods of preparation. The main advantages and disadvantages of a wide range of preparation methods were discussed in this paper. Different sources of N were also analyzed, and their individual impact on the characteristics of N–TiO2 was assessed. The core of this paper was focused on the large spectrum of analytical techniques to detect modifications in the TiO2 structure from the incorporation of N. The effect of N–TiO2 co-doping was also analyzed, as well as the main characteristics that are relevant to the performance of the catalyst, such as its particle size, surface area, quantum size effect, crystalline phases, and the hydrophilicity of the catalyst surface. Powder is the most used form of N–TiO2, but the economic benefits and applications involving continuous reactors were also analyzed with supported N–TiO2. Moreover, the degradation of contaminants emerging from water and wastewater using N–TiO2 and co-doped TiO2 was also discussed.