Hui Niu,Huan Lin,Huiting Zhang,Longfeng Hu,Gangqiang Yu,Shuhong Wu,Jinlin Long,Quan-Fu An
Photocatalytic hydrogen evolution presents a sustainable method for clean energy generation, yet its efficiency remains limited by insufficient charge separation and transfer. Herein, we report a novel strategy to enhance photocatalytic efficiency by integrating both bulk and surface electric fields within self-assembled supramolecular photocatalyst. We synthesized perylene 3,4-dicarboxylic acid (PDA) with a large dipole moment and polar carboxyl groups, which self-assembles into ultrathin 2D nanosheets in water. The accumulation of dipole moments induces a bulk electric field, enabling ultrafast exciton dissociation into free charges. Concurrently, the exposed carboxyl groups generate a surface electric field, facilitating efficient charge extraction and transfer on the surface for proton reduction. The synergistic interplay between bulk and surface electric fields results in an impressive photocatalytic hydrogen production rate of 3.2 mmol g⁻¹ h⁻¹ , significantly surpassing that of the other perylene-based nanosheets relying solely on either bulk or surface electric fields. This study offers valuable insights into the distinct roles of bulk and surface electric fields in photocatalytic processes, and introduces a new design paradigm for photocatalysts to enhance solar-to-hydrogen conversion efficiency.
Shuai Yue,Guobin Xiao,Qiujin Shi,Xijiao Mu,Manke Zhang,Mingzheng Xie,Jing Cao
As a promising technology with both environmental and economic benefits, photocatalytic CO 2 conversion relies heavily on photo-carrier transport properties. However, oxide photocatalysts often face a significant limitation due to their restricted carrier transport distances, typically below 100 nm. Here, a surface electric field regulation strategy is proposed that enhances carrier transport in metal oxide photocatalysts by integrating specific porphyrin supramolecular assemblies. Through spin-coating, monoamine metal porphyrin assemblies are uniformly deposited on the BiVO 4 photocatalyst via van der Waals interactions. The electronic coupling between amine groups and Co atoms in adjacent porphyrin units generates unoccupied orbitals, which facilitate the accumulation of holes within the Co-porphyrin supramolecular system. This coupling induces interfacial electron redistribution and charge density reorganization, creating an intense surface electric field on BiVO 4 with an intensity of 17.4 V m −1 . As a result, the mobility of photo-carriers within BiVO 4 is significantly enhanced, extending the hole diffusion length from 46.7 to 232.9 nm and enabling more efficient charge extraction at the surface. This improvement results in a 7.3-fold increase in the photocatalytic CO 2 reduction performance, achieving an external quantum efficiency of 1.86%. The proposed approach offers a generalizable method for enhancing photo-carrier properties in photocatalytic systems.
危险品化学品经营许可证（带存储）