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Effective wastewater treatment is essential due to the dye environmental threats. Photocatalysis offers an eco-friendly dye degradation solution. Herein, we report a double Z-scheme photocatalyst, i.e. LaFeO3/Boron-doped g-C3N4/Fe2O3 (LFO/B-CN/FO), fabricated via a hydrothermal method. The formation of this ternary system is supported by structural, surface, and morphological analyses. Differential scanning calorimetry and thermal gravimetric analysis demonstrated the crystallization behavior of the composite. Because of synergetic effects in the ternary composite and boron doping, the optical band gap energy is reduced to 1.6 eV. Under visible light irradiation, the LFO/B-CN/FO nanocomposite degraded navy-blue dye by 98% in 130 min at neutral pH, surpassing CN, B-CN, and binary composites of B-CN with LFO and FO. The degradation process was rationalized using pseudo-first- and pseudo-second-order kinetic models, which confirmed high catalytic efficiency. The double Z-scheme heterojunction enhanced light absorption, charge separation, and carrier lifetime, hence improving the photocatalytic activity. Overall, the as-fabricated LFO/B-CN/FO ternary composite outperformed reference catalysts in terms of chemical reactivity, optical characteristics, and electrical performance. This work opens up a new route for the design and fabrication of double Z-scheme ternary composite photocatalysts for potential wastewater treatment and renewable energy applications. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2), with a two-dimensional (2D) structure, has attracted huge research interest due to its unique electrical, optical, and physicochemical properties. MoS2 has been used as a co-catalyst for the synthesis of novel heterojunction composites with enhanced photocatalytic hydrogen production under solar light irradiation. In this review, we briefly highlight the atomic-scale structure of MoS2 nanosheets. The top-down and bottom-up synthetic methods of MoS2 nanosheets are described. Additionally, we discuss the formation of MoS2 heterostructures with titanium dioxide (TiO2), graphitic carbon nitride (g-C3N4), and other semiconductors and co-catalysts for enhanced photocatalytic hydrogen generation. This review addresses the challenges and future perspectives for enhancing solar hydrogen production performance in heterojunction materials using MoS2 as a co-catalyst. [ABSTRACT FROM AUTHOR]

• ZnWO 4 /NiWO 4 S-scheme photocatalysts are successfully synthesized. • The photocatalytic activity of ZnWO 4 is enhanced by modification of NiWO 4. • S-scheme heterojunction formation promotes the separation efficiency of photogenerated carriers. Water pollution poses health risks to humans and ecosystems, with long-term accumulation of tetracyclines causing toxicity, disrupting cartilage tissue, and drug resistance, while antibiotics affect plant hormones and microorganisms. Scientists are exploring high-performance materials for antibiotic degradation and antibiotic-resistant bacteria, using photocatalytic techniques as a cost-effective solution. In this study, ZnWO 4 /NiWO 4 composite-based photocatalysts with varying mass ratios (from 10 % to 30 %) were successfully synthesized using hydrothermal and high-temperature calcination. The photocatalytic activity of the ZnWO 4 /NiWO 4 nanocomposite first increases as the mass of NiWO 4 increases and then declines progressively. Different techniques were used to characterize its morphological structure and optical characteristics. The photocatalytic activity of ZnWO 4 /NiWO 4 was evaluated using tetracycline hydrochloride as a model pollutant. The study found that a 25 % ZnWO 4 /NiWO 4 composite ratio yielded the highest photocatalytic activity. The degradation efficiency was enhanced to 90.7 % under exposing it to visible light for 2 h. This enhanced photocatalytic activity is attributed to the S-scheme heterojunction formed by ZnWO 4 and NiWO 4 , which promotes the separation of charge carriers. Remarkably 1 h of testing under simulated solar irradiation demonstrated that 25 % ZnWO 4 /NiWO 4 exhibited a strong antibacterial effect. Finally, this study will lead to a method for fabricating eco-friendly nanomaterials for environmental remediation and antibacterial activities. [Display omitted] [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis is an efficient, cost effective and promising approach for pollution control and environmental remediation, however, the fast recombination of excitons inhibits the practical applications of photocatalysis. The construction of heterojunction is a viable solution that reduces the recombination of excitons by transfer of charge carriers resulting in improved catalytic performance. Here, the fabrication of a sunlight-active TiO 2 -g-C 3 N 4 photocatalyst by the hydrothermal process for the degradation of Congo red dye is reported. After characterization, TiO 2 -g-C 3 N 4 heterojunction was employed as a photocatalyst for the sunlight-light-assisted photodegradation of Congo red dye. The fabricated g-C 3 N 4 and TiO 2 -g-C 3 N 4 exhibited 52 % and 100 % photodegradation of 50 mL (100 mg/L) of Congo red dye by irradiation in sunlight for 180 min, respectively. The hydroxyl radicals were major species involved in the photodegradation of Congo red dye. [ABSTRACT FROM AUTHOR]

Phosphorus doped g-C 3 N 4 (P/g-C 3 N 4) polymer has been prepared by using ionic liquid 1-Butyl-3-methylimidazolium hexafluorophosphate providing the P source. P/g-C 3 N 4 shows a high photoactivity for photodecomposition of methylene blue and tetracycline hydrochloride as an emerging water pollutant. The photocatalytic activity of optimized 3%-P/g-C 3 N 4 sample (3% in mass ratio of P) is 3 times improved compared to g-C 3 N 4. This improvement in activities attribute to the new generated energy levels in the bandgap of g-C 3 N 4 that originates from the doping of phosphorus. Photoelectrochemical and photoluminescence results confirmed the high charge separation rates and low charge recombination rates after P doping in g-C 3 N 4. The present study showed a simple method of preparation of non-metal ions doped porous g-C 3 N 4 photocatalysts for the decomposition of antibiotics in polluted water. Image 1 • Porous P doped g-C 3 N 4 nanosheets were synthesized with ionic liquid as former. • P-doping was helpful to promote separation of photo-generated carriers in g-C 3 N 4. • P-doping narrowed the bandgap and enhanced light utilization of g-C 3 N 4. • P-doped g-C 3 N 4 achieved high potodegradation activity for organic pollutants. [ABSTRACT FROM AUTHOR]

This work incorporates a variety of conjugated donor-acceptor (DA) co-monomers such as 2,6-diaminopurine (DP) into the structure of a polymeric carbon nitride (PCN) backbone using a unique nanostructure co-polymerization strategy and examines its photocatalytic activity performance in the field of photocatalytic CO2 reduction to CO and H2 under visible light irradiation. The as-synthesized samples were successfully analyzed using different characterization methods to explain their electronic and optical properties, crystal phase, microstructure, and their morphology that influenced the performance due to the interactions between the PCN and the DPco-monomer. Based on the density functional theory (DFT) calculation result, pure PCN and CNU-DP15.0 trimers (interpreted as incorporation of the co-monomer at two different positions) were extensively evaluated and exhibited remarkable structural optimization without the inclusion of any symmetry constraints (the non-modified sample derived from urea, named as CNU), and their optical and electronic properties were also manipulated to control occupation of their respective highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Also, co-polymerization of the donor–acceptor 2,6-diamino-purine co-monomer with PCN influenced the chemical affinities, polarities, and acid–base functions of the PCN, remarkably enhancing the photocatalytic activity for the production of CO and H2 from CO2 by 15.02-fold compared than that of the parental CNU, while also improving the selectivity. [ABSTRACT FROM AUTHOR]

In the current energy crisis, converting solar-thermal energy into chemical forms has become paramount. Within the broad spectrum of light-mediated catalysis, which includes heat and photocatalysis (relevant to processes like organic transformations, water splitting, and CO2 reduction), photothermal catalysis is a critical avenue for transforming solar energy into chemical or thermal forms via light-matter interactions. However, challenges persist, notably in conventional semiconductor photocatalysts. These challenges encompass the suboptimal harnessing of solar radiation, electron-hole pair recombination, limited exposure of reactive sites, and the complex endeavor of establishing the structure-activity relationship. This state-of-the-art review sharply focuses on photothermal catalytic materials associated with water splitting, CO2 conversion, and the breakdown of organic contaminants. Distinctively, it provides a profound experimental and theoretical insight into the application of various materials in photothermal catalysis, representing a pioneering consolidation. Furthermore, the article delves deep into the barriers to commercialization, offering a robust discussion of the inherent challenges and their prospective remedies. Our findings underscore that enhancing catalytic efficiency is achievable through strategic structural, surface, and compositional modifications. Techniques such as doping, the formation of heterojunctions using Z- and S- schemes, multi-metal incorporation, and the synergistic application of materials prove beneficial. Equally pivotal is the introduction of supporting materials to curb agglomeration, the incorporation of porosity, and the design of varied 3D structures. Collectively, these innovative approaches enhance surface area, modulate band gaps, widen light absorption capacity, minimize charge recombination, and, consequently, pave the way for the evolution of optimal catalysts suited for photothermal applications. In the quest to address energy challenges, this comprehensive review delves into the pivotal role of photothermal catalysis in converting solar-thermal energy into valuable chemical forms. Highlighting the inherent limitations of conventional semiconductor photocatalysts, it presents a synthesis of advanced materials tailored for water splitting, CO2 conversion, and organic contaminant decomposition. Through in-depth analysis, the paper underscores innovative techniques like doping, heterojunction formation, and multi-metal incorporation. By emphasizing strategic structural and compositional modifications, the review offers insights into the roadmap for optimizing photothermal catalytic efficiency and paves the way for future commercialization. [Display omitted] • Delivers groundbreaking insights into materials for photothermal catalysis including water splitting and pollution reduction. • Provides solutions to commercialization issues including solar radiation harnessing and recombination reduction. • Shows efficiency gains through structural modifications, doping, and heterojunctions. • Emphasizes techniques like material synergy and 3D structuring to enhance catalyst performance. • Details optimization strategies for photothermal catalysts, aiming at sustainable energy and environmental solutions. [ABSTRACT FROM AUTHOR]

It's highly desired to design and fabricate effective α-Fe 2 O 3 -based photocatalysts by increasing the surface area, promoting the charge separation and providing catalytic function. Herein, specific surface area-enlarged α-Fe 2 O 3 (SE-FO) nanoparticles have been successfully synthesized by a functional molecule-modulated phase-separated hydrothermal method, with high photocatalytic activities for CO 2 conversion and phenol degradation. The photocatalytic activities of SE-FO could be greatly improved by coupling nano-sized BiPO 4 via an in-situ introduction method. This is attributed to the coupled BiPO 4 as a high-energy platform to accept photogenerated electrons from α-Fe 2 O 3 so as to enhance the charge separation mainly by means of surface photovoltage spectra and fluorescence spectra-related to the amount of produced •OH species. Moreover, the photocatalytic activities are further improved by introducing a proper amount of nanocrystalline CuO via a simple impregnation process. It is confirmed based on the temperature-programmed desorption and electrochemical reduction measurements that the improved photoactivity is attributed to the introduced CuO as the co-catalyst for promoting electron-induced reduction reactions. Remarkably, the optimized α-Fe 2 O 3 nanocomposite exhibits about 3-time photoactivity improvement compared with the pristine α-Fe 2 O 3. This work would provide a feasible route to fabricate high-activity α-Fe 2 O 3 -based photocatalysts for CO 2 conversion and phenol degradation. Photocatalytic activities of α-Fe 2 O 3 nanoparticles are improved after co-modifying BiPO 4 and CuO, attributed to the promoted photogenerated electron transfer, and the provided catalytic functions. Image 1 • α-Fe 2 O 3 nanoparticles with increased surface area have been synthesized by a molecule-modulated hydrothermal method. • Resulting α-Fe 2 O 3 nanoparticles exhibit high photocatalytic activities for CO 2 conversion and pollutant degradation. • Photocatalytic activities of α-Fe 2 O 3 are further improved after co-modifying BiPO 4 and CuO with a proper amount. • Used nano-sized BiPO 4 is taken as a high-energy platform to accept photogenerated electrons from α-Fe 2 O 3. • Introduced nano-sized CuO provides a catalytic function to electron-induced reduction reactions. [ABSTRACT FROM AUTHOR]

• TiO 2 /AC is fabricated for photocatalytic degrading high-concentration pollutants. • The activities are improved by constructing heterojunction with SrTiO 3. • The activities are further improved by modifying phosphoric acid. • Exceptional photoactivities mainly depend on the enhanced charge separation. • Charge separation is due to the improved charge transfer and O 2 adsorption. It is highly desired to develop efficient TiO 2 -based nano-photocatalysts with excellent recycling properties for practical application to degrade high-concentration pollutants. Herein, TiO 2 nanoparticles have been successfully modified by coupling activated carbon (AC), constructing heterojunction with SrTiO 3 and modifying with phosphoric acid. It is clearly demonstrated that the as-prepared nano-photocatalysts exhibit exceptional photoactivities for degrading high-concentration pollutants like 2,4-dichlorophenol (2,4-DCP) and bisphenol A (BPA), both with ∼3-time activity enhancement compared to commercial P25 TiO 2. Based on the surface photovoltage responses and the fluorescence spectra related to the formed OH amounts, it is deduced that the exceptional photocatalytic activities are attributed to the coupled AC for accepting electrons and promoting reactant adsorption, to the formed SrTiO 3 for inhibiting the anatase TiO 2 crystallite growth to increase the surface area and promoting the charge separation, and to the modified phosphate groups for promoting the adsorption of O 2 to enhance the charge separation. Furthermore, it is demonstrated through the radical trapping experiments that the photogenerated hydroxyl radicals could be dominant for the photocatalytic degradation of 2,4-DCP. This work would provide a feasible route to obviously enhance the photocatalytic activities of TiO 2 -based nano-photocatalysts for the environmental remediation with good recycling properties. [ABSTRACT FROM AUTHOR]