Abstract Methane (CH 4 ) oxidation to high value chemicals under mild conditions through photocatalysis is a sustainable and appealing pathway, nevertheless confronting the critical issues regarding both conversion and selectivity. Herein, under visible irradiation (420 nm), the synergy of palladium (Pd) atom cocatalyst and oxygen vacancies (OVs) on In 2 O 3 nanorods enables superior photocatalytic CH 4 activation by O 2 . The optimized catalyst reaches ca. 100 μmol h −1 of C1 oxygenates, with a selectivity of primary products (CH 3 OH and CH 3 OOH) up to 82.5%. Mechanism investigation elucidates that such superior photocatalysis is induced by the dedicated function of Pd single atoms and oxygen vacancies on boosting hole and electron transfer, respectively. O 2 is proven to be the only oxygen source for CH 3 OH production, while H 2 O acts as the promoter for efficient CH 4 activation through ·OH production and facilitates product desorption as indicated by DFT modeling. This work thus provides new understandings on simultaneous regulation of both activity and selectivity by the synergy of single atom cocatalysts and oxygen vacancies. 

/pdf/synergy-of-pd-atoms-and-oxygen-vacancies-on-in2o3-for-1tniu4b8.pdf

Synergy of Pd atoms and oxygen vacancies on In2O3 for methane conversion under visible light

Methane hydrate and shale gas are predicted to have substantial reserves, far beyond the sum of other fossil fuels. Using methane instead of crude oil as a building block is, thus, a very attractive strategy for synthesizing valuable chemicals. Because methane is so inert, its direct conversion needs a high activation energy and typically requires harsh reaction conditions or strong oxidants. Photocatalysis, which employs photons operated under very mild conditions, is a promising technology to reduce the thermodynamic barrier in direct methane conversion and to avoid the common issues of overoxidation and catalyst deactivation. In this Review, we cover the development of photocatalysts and co-catalysts, including the use of inorganic materials and polymeric semiconductors, and explain how the use of batch or flow reaction systems affects the reaction kinetics and product selectivity. We also discuss efforts to understand the underlying reaction mechanisms from both a photophysical and a chemical perspective. Finally, we present our view of the challenges facing this field and suggest potential solutions. Methane, as a replacement for crude oil, can be converted into valuable chemicals through photocatalysis. This Review discusses the design of promising photocatalytic systems and strategies to understand their reaction mechanisms and outlines the most pressing questions still facing the field. 

/pdf/methane-transformation-by-photocatalysis-1m2ujcwt.pdf

Methane transformation by photocatalysis

Efficient Photocatalytic Degradation of the Persistent PET Fiber-Based Microplastics over Pt Nanoparticles Decorated N-Doped TiO2 Nanoflowers

In recent years, nanozyme-photothermal therapy (NPT) has attracted enormous interests owing to their enhanced therapeutic effects and less adverse effects in the treatment of infectious diseases. However, the development of nanozyme-photothermal agents (NPAs) that can rapidly, efficiently and synergistically combating pathogenic bacteria remains a huge challenge due to the limitation of size effect. Herein, by decorating platinum nanozymes on Zn-based photosensitizer, we report a novel metal-organic framework (MOF)-derived hybrid nanozymes antibacterial strategy for enhanced NPT. This strategy can not only prevent the aggregation of platinum nanozymes and effectively reduce the mass transfer resistance during the kinetic reaction, but also inhibit the photoelectron-hole recombination in the process of photothermal therapy (PTT) and improve the photothermal conversion performance. In the presence of a low concentration of hydrogen peroxide (H2O2), the superior nanocatalytic activity of the MOF-derived hybrid nanozymes can effectively catalyze the release of H2O2 to generate toxic hydroxyl radical (•OH), resulting in the increase of bacterial membrane permeability and thermal sensitivity. Once the near-infrared laser is introduced, the nanozyme-photothermal antibacterial platform can play the role of “nanoknife” to further induce the death of the damaged bacteria by physical cutting. In vitro and vivo in antibacterial assays confirm that the MOF-derived hybrid nanozymes have excellent antibacterial properties, which can serve as an antibacterial candidate with negligible adverse effect. Therefore, this work will open a new avenue for MOF-derived hybrid nanozymes in biomedical application.

In situ fabrication of metal-organic framework derived hybrid nanozymes for enhanced nanozyme-photothermal therapy of bacteria-infected wounds

In recent years, nanozyme-photothermal therapy (NPT) has attracted enormous interests owing to their enhanced therapeutic effects and less adverse effects in the treatment of infectious diseases. However, the development of nanozyme-photothermal agents (NPAs) that can rapidly, efficiently and synergistically combating pathogenic bacteria remains a huge challenge due to the limitation of size effect. Herein, by decorating platinum nanozymes on Zn-based photosensitizer, we report a novel metal-organic framework (MOF)-derived hybrid nanozymes antibacterial strategy for enhanced NPT. This strategy can not only prevent the aggregation of platinum nanozymes and effectively reduce the mass transfer resistance during the kinetic reaction, but also inhibit the photoelectron-hole recombination in the process of photothermal therapy (PTT) and improve the photothermal conversion performance. In the presence of a low concentration of hydrogen peroxide (H2O2), the superior nanocatalytic activity of the MOF-derived hybrid nanozymes can effectively catalyze the release of H2O2 to generate toxic hydroxyl radical (•OH), resulting in the increase of bacterial membrane permeability and thermal sensitivity. Once the near-infrared laser is introduced, the nanozyme-photothermal antibacterial platform can play the role of “nanoknife” to further induce the death of the damaged bacteria by physical cutting. In vitro and vivo in antibacterial assays confirm that the MOF-derived hybrid nanozymes have excellent antibacterial properties, which can serve as an antibacterial candidate with negligible adverse effect. Therefore, this work will open a new avenue for MOF-derived hybrid nanozymes in biomedical application. 

The high inertness of the C–H bond makes the photocatalytic methane conversion a significant challenge. The platinum nanoparticle is a promising cocatalyst for CH4 activation, while the study of it...

Yan Wang

Papers

Exploring the Size Effect of Pt Nanoparticles on the Photocatalytic Nonoxidative Coupling of Methane