Tuning Dynamic Structural Evolution of Bi24O31Cl10 for Enhancing Piezo-Photocatalytic Nitrogen Oxidation to Nitrate.

Direct nitrogen oxidation into nitrate under ambient conditions presents a promising strategy for harsh and multistep industrial processes. However, the dynamic structural evolution of active sites in surface reactions constitutes a highly intricate endeavor and remains in its nascent stage. Here, we constructed a Bi24O31Cl10 material with moiré superlattice structure (BCMS) for direct piezo-photocatalytic oxidation of nitrogen into nitrate. Excitingly, BCMS achieved excellent nitric acid production (15.44 mg g-1 h-1) under light and pressure conditions. Detailed experimental results show that the unique structure extracts the local strain tensor from the constricting Bi-Bi bond and Bi-O bond for internal structural reconstruction, which promotes the formation of electron and reactive molecule vortexes to facilitate charge transfer as well as N2 and O2 adsorption. Ultimately, these initiatives strengthen electron exchange between the superoxide radical and nitrogen as well as the binding strength of multiple intermediates, which swayingly adjusts the reaction path and energy barriers.

Regulating local molecular polarization of triazine-PDI based polymer for high-efficient photocatalytic coupling of benzylamine.

Designing a robust built-in electric field (BF) is a charming strategy for enhancing the separation and transportation of charges via introducing large π-conjugated molecules. However, it has flexible or semiflexible geometries, which significantly disorder the crystalline and deteriorated the built-in electric field. Here, a straightforward tactic for creating a cyano-functionalized smaller D (benzene) - A (triazine) units in PDI- triazine based polymer (PDIMB) to enhance intrinsic molecule dipole has been proposed. The density functional theory (DFT) calculation revealed that the modification of smaller D-A groups destroyed the π-localization of charges, which enhanced the molecular dipole and the BF for promoting the exciton dissociation and charge transfer. Moreover, it not only exposed number of active sites, but also enhanced the interfacial molecular interacting. Therefore, PDIMB-2 exhibits high activity (24.5 mmol g-1 h-1) and selectivity (>99%) for the photooxidation of benzylamine to N-benzylidenebenzylamine under mild conditions. Our work offers a potential and simple synthetic option for enhancing the built-in electric field of polymer.