Photogenerated outer electric field induced electrophoresis of organic nanocrystals for effective solid-solid photocatalysis

Etched BiVO4 photocatalyst with charge separation efficiency exceeding 90

Charge separation of particulate photocatalysts has been considered as the rate-determining step in artificial photocatalysis since the finding of Honda-Fujishima effect, whose efficiency is generally much lower than that of natural photosynthesis. To approach its upper limit, it requires the photoexcited electrons and holes be efficiently transferred to the spatially separated redox reaction sites over a single photocatalyst particle. Herein, it is demonstrated the spatial charge separation among facets of BiVO4:Mo can be notably promoted by creating an electron transfer layer. It not only favors electrons to transfer to its surface, but also promotes the built-in electric field intensity of the inter-facet junction by over 10 times. Consequently, the charge separation efficiency of the modified BiVO4:Mo with loading of CoFeOx oxidation cocatalyst exceeds 90% at 420 nm, comparable to that of the natural photosynthesis system, over which notably enhanced photocatalytic activities are achieved. Our findings demonstrate the effectiveness of electron transfer layer in intensifying charge separation of particulate photocatalysts.

Boosting Visible-Light-Driven Hydrogen Evolution Enabled by Iodine-Linked Magnetically Curved Graphene with Mobius-like Electronic Paths

Materials with high electron transfer performance remain a key focus in photocatalytic research, as they can effectively promote the separation of photogenerated carriers and enhance the utilization efficiency of photogenerated electrons. To enhance the effective utilization of photogenerated electrons, the MSIG material was prepared by incorporating the iodine clusters and magnetic Fe3O4 into the as-synthesized crumpled graphene oxide (CGO) to construct Möbius-like electronic transmission pathways. The introduction of magnetic groups optimized the spin orientation of electrons, facilitating directional electron transport and thereby enhancing the photocatalytic efficiency of the material. Experimental results reveal that, in visible light-driven hydrogen production reactions, the eosin Y (EY)-sensitized Pt-Fe3O4-MSIG catalyst exhibits outstanding catalytic performance, with a hydrogen production rate of 1.48 mL/h, which is 15 times higher than that of the Pt-Fe3O4 catalyst. Photoelectrochemical analyses show a significant increase in the catalyst's fluorescence lifetime, attributed to the Möbius strip-like electron transport channels within the material. Theoretical calculations further support this by demonstrating that the bandgap widening of the CGO reduces the recombination probability of photogenerated carriers, thereby improving their average lifetime. This study offers a novel approach for the design of visible-light-driven photocatalytic materials.

A perspective on field-effect in energy and environmental catalysis

The development of catalytic technologies for sustainable energy conversion is a critical step toward addressing fossil fuel depletion and associated environmental challenges. High-efficiency catalysts are fundamental to advancing these technologies. Recently, field-effect facilitated catalytic processes have emerged as a promising approach in energy and environmental applications, including water splitting, CO2 reduction, nitrogen reduction, organic electrosynthesis, and biomass recycling. Field-effect catalysis offers multiple advantages, such as enhancing localized reactant concentration, facilitating mass transfer, improving reactant adsorption, modifying electronic excitation and work functions, and enabling efficient charge transfer and separation. This review begins by defining and classifying field effects in catalysis, followed by an in-depth discussion on their roles and potential to guide further exploration of field-effect catalysis. To elucidate the theory-structure-activity relationship, we explore corresponding reaction mechanisms, modification strategies, and catalytic properties, highlighting their relevance to sustainable energy and environmental catalysis applications. Lastly, we offer perspectives on potential challenges that field-effect catalysis may face, aiming to provide a comprehensive understanding and future direction for this emerging area.

Local weak hydrogen bonds induced dipole-dipole interactions in polymer for enhancing photocatalytic oxidation

Functionalizing organic polymers is an effective strategy for enhancing their photocatalytic performance. However, this approach is currently limited by specific motifs, complex preparation methods, and an unclear electron transfer mechanism. Here, we present a meticulously designed structure of perylene diimide connected with poly (barbituric acid trimer) through self-assembled hydrogen bonding. In particular, the local chemical environment of the two components is adjusted by hydrogen bond-induced dipole-dipole interactions, leading to the emergence of a significant inherent electric field. Additionally, the formation of hydrogen bonds provides electronic pathways that facilitate charge transfer from perylene to adjacent units. Moreover, the distinctive electronic structure enhances polarity transfer and improves activation and adsorption capabilities for reactive molecules. Ultimately, B-PDI exhibits outstanding oxidation rates for benzylamine to N-benzylidene-benzylamine (10.03 mmol g-1h-1) and selectivity (>99.99 %). Our work offers a widely popular approach for enhancing the photocatalytic activity of organic semiconductor materials by constructing hydrogen bonds in heterogeneous molecules.

Photothermal Mineralization of Polyolefin Microplastics via TiO2 Hierarchical Porous Layer-Based Semiwetting Air-Plastic-Solid Interfaces

Photo-mineralization of microplastics under mild conditions has emerged as a promising solution to plastic waste disposal. However, the inadequate contact between oxygen, water-insoluble polyolefin microplastics, and photocatalysts remains a critical issue. In this study, a TiO2 hierarchical porous layer (TiO2-HPL) photocatalyst is presented to establish air-plastic-solid triphase interfaces for the photothermal mineralization of polyolefins. The wettability of the TiO2-HPL-based triphase interface is finely controlled from plastophobic to plastophilic. High-resolution imaging and finite element simulation demonstrate the significance of a semiwetting state in achieving multidirectional oxygen diffusion through the hierarchical pore structure while maintaining sufficient contact between the plastic phase and photocatalysts. For low-density polyethylene, the TiO2-HPL achieves a photothermal mineralization rate of 5.63 mmol g-1 h-1 and a conversion of 26.3% after 20 h of continuous irradiation. Additionally, the triphase photocatalytic system with semiwetting gas-plastic-solid interfaces shows good universality for various polyolefin reagents and products, illustrating its potential in achieving efficient photothermal mineralization of non-degradable microplastics.