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Methane as the main component in natural gas is a promising chemical raw material for synthesizing value‐added chemicals, but its harsh chemical conversion process often causes severe energy and environment concerns. Photocatalysis provides an attractive path to active and convert methane into various products under mild conditions with clean and sustainable solar energy, although many challenges remain at present. In this review, recent advances in photocatalytic methane conversion are systematically summarized. As the basis of methane conversion, the activation of methane is first elucidated from the structural basis and activation path of methane molecules. The study is committed to categorizing and elucidating the research progress and the laws of the intricate methane conversion reactions according to the target products, including photocatalytic methane partial oxidation, reforming, coupling, combustion, and functionalization. Advanced photocatalytic reactor designs are also designed to enrich the options and reliability of photocatalytic methane conversion performance evaluation. The challenges and prospects of photocatalytic methane conversion are also discussed, which in turn offers guidelines for methane‐conversion‐related photocatalyst exploration, reaction mechanism investigation, and advanced photoreactor design. [ABSTRACT FROM AUTHOR]

Methane conversion to higher hydrocarbons requires harsh reaction conditions due to high energy barriers associated with C−H bond activation. Herein, we report a systematic investigation of photocatalytic oxidative coupling of methane (OCM) over transition‐metal‐loaded ZnO photocatalysts. A 1 wt % Au/ZnO delivered a remarkable C2‐C4 hydrocarbon production rate of 683 μmol g−1 h−1 (83 % C2‐C4 selectivity) under light irradiation with excellent photostability over two days. The metal type and its interaction with ZnO strongly influence the selectivity toward C−C coupling products. Photogenerated Zn+‐O− sites enable CH4 activation to methyl intermediates (*CH3) migrating onto adjacent metal nanoparticles. The nature of the *CH3‐metal interaction controls the OCM products. In the case of Au, strong d‐σ orbital hybridization reduces metal‐C−H bond angles and steric hindrance, thereby enabling efficient methyl coupling. Findings indicate the d‐σ center may be a suitable descriptor for predicting product selectivity during OCM over metal/ZnO photocatalysts. [ABSTRACT FROM AUTHOR]

Photocatalytic CO2 reduction reaction (CO2RR) is an attractive process to convert CO2 into valuable chemicals. But this reaction is often restricted by the poor mass transfer of CO2 in the liquid phase. Here, we have developed a triphase photocatalytic CO2RR system by supporting Ag‐decorated TiO2 nanoparticles at a gas–water boundary with hydrophobic–hydrophilic abrupt interfacial wettability. Such a triphase system allows the rapid delivery of gas‐phase CO2 to the surface of photocatalysts while maintaining an efficient water supply and uncovered active sites. Ag‐TiO2 supported at the gas–water boundary showed a CO2 reduction rate of 305.7 μmol g−1 h−1, without hole scavengers, approximately 8 times higher than the nanoparticles dispersed in the liquid phase. Even using diluted CO2 (10 %) as the reactant, the CO2RR activity was superior to most reported Ag‐TiO2 based photocatalysts using pure CO2. The findings provide a general strategy to promote the interfacial CO2 mass transfer to improve photoactivity and selectivity. [ABSTRACT FROM AUTHOR]

Photothermal CO2 reduction is an efficient and sustainable catalytic path for CO2 treatment. Here, we successfully fabricated a novel series of Ni-based catalysts (Ni-x) via H2 reduction of NiAl-layered double hydroxide nanosheets at temperatures (x) ranging from 300 to 600 °C. With the increase of the reduction temperature, the methane generation rate of the Ni-x catalyst for photothermal CO2 hydrogenation gradually increased under ultraviolet-visible-infrared (UV-vis-IR) irradiation in a flow-type system. The Ni-600 catalyst showed a CO2 conversion of 78.4%, offering a CH4 production rate of 278.8 mmol·g−1h−1, with near 100% selectivity and 100 h long-term stability. Detailed characterization analyses showed metallic Ni nanoparticles supported on amorphous alumina are the catalytically active phase for CO2 methanation. This study provides a possibility for large-scale conversion and utilization of CO2 from a sustainable perspective. [ABSTRACT FROM AUTHOR]

Photocatalytic advanced oxidation has been widely studied for purifying organic polluted water bodies. The molding of powder catalyst is able to solve the problems of difficult recycling and secondary pollution, and it further promotes the practical application of photocatalytic materials. In this work, PAN and PVDF are used as precursors to prepare polymer blended fiber membranes using electrostatic spinning technique. In order to achieving the degradation of Rh-B via photocatalysis, PAPV@MT photocatalytic membrane is prepared in company with acrylic acid modification and in-situ growth of MoS 2 /TiO 2 via hydrothermal method. As a result, the photocatalytic film exhibits good stretchability, flexibility, and high catalytic degradation capacity. At the same time, the special structure of the hydrophobic surface on the membrane layer enables the photocatalytic membrane to hold a three-phase, i.e., solid-liquid-gas. Considering Rh-B as target contaminant, waste water can be decolorized within 150 min with a removal rate of 80%, benefiting from the introduction of MoS 2. It promotes the separation of electron-hole pairs, so that its catalytic capacity is significantly enhanced. Therefore, the membranes reported here provide ideas for practical applications, with properties of stable, highly catalytic active photocatalytic. ● Preparing membrane s with blended fibers to enhance its mechanical properties. ● In-situ growth of MoS 2 /TiO 2 via grafting treatment. ● Constructing three-phase reaction to enhance the yield of reactive radicals. ● Achieving performances of efficient, environmentally friendly and easy to recycle. [ABSTRACT FROM AUTHOR]

[Display omitted] • The OCN/Co 3 O 4 catalyst was utilized to individually eliminate TCs and E.coli within the PMS system. • OCN/Co 3 O 4 /Vis/PMS exhibited 99.2% of tetracycline degradation within 20 min. • The OCN/Co 3 O 4 catalyst exhibits outstanding catalytic activity and stability. • Activation mechanism of OCN/Co 3 O 4 with respect to PMS was elucidated. The widespread use of graphitic carbon nitride (CN) for environmental pollutant removal has been hampered by intrinsic limitations, notably facile electron-hole recombination and a limited surface area. This work successfully synthesized OCN/Co 3 O 4 composite materials. Furthermore, the implementation of a peroxymonosulfate (PMS) reaction system remarkably enhanced the material's capability to degrade Escherichia coli (E. coli) and tetracycline hydrochloride (TC). Compared with CN, the composite material possessed a notably larger specific surface area, affording it a profusion of reactive sites. Additionally, the replacement of carbon atoms with oxygen atoms in the original CN structure profoundly altered its electronic configuration. The characterization through UV–Vis diffuse reflectance spectra, photoluminescence, transient photocurrent responses, and electrochemical impedance spectroscopy also confirmed the excellent optical and electrochemical attributes of OCN/Co 3 O 4. Experimental results illustrated OCN/Co 3 O 4 /Vis/PMS completely degraded E. coli at an initial concentration of 1 × 107 CFU mL−1 within 1 h and reduced TC with the adding concentration of 10 mg/L by 99.2% in only 20 min. An analysis was conducted on reactive oxygen species (ROS) using electron paramagnetic resonance spectroscopy and radical quenching experiments. The test results demonstrated the generation of ROS including •O 2 −, •OH, h+, and SO 4 •− within the reaction system. This work explored the degradation mechanism in the OCN/Co 3 O 4 /Vis/PMS system, providing innovative insights for the design of eco-friendly, efficient catalysts as well as the enhancement of TC and E. coli degradation through the synergistic activation of photocatalytic PMS. [ABSTRACT FROM AUTHOR]

Solar-to-chemical energy conversion is a challenging subject for renewable energy storage. Solar-driven hydrogen peroxide (H 2 O 2) synthesis is a sustainable and potentially economic technology. Despite great efforts in catalyst engineering, photocatalytic H 2 O 2 production is usually limited by the sluggish oxygen diffusion and H 2 O 2 decomposition side reactions, leading to poor apparent photocatalytic H 2 O 2 production efficiency. Herein, we developed a fluid triphase system that enables both the efficient interfacial oxygen mass transfer and the inhibited H 2 O 2 decomposition side reactions. Such a synergistic effect endowed a residue-free H 2 O 2 production rate of 6.03 μmol h−1 from pure water and oxygen without using any sacrificial agent or additive, with over 120 h continuous irradiation stability. We further designed a photosynthesis-concentration tandem system to produce high concentration H 2 O 2 (10 mM), which demonstrated an effective water disinfection capability as a representative application. [Display omitted] • A fluid triphase system was developed to achieve residue-free H 2 O 2 production. • The triphase system enables efficient interfacial oxygen mass transfer. • The fluid system can inhibit H 2 O 2 decomposition side reactions. • A concentration tandem system was designed to produce high-concentration H 2 O 2. [ABSTRACT FROM AUTHOR]