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.

Electronic configuration inversion in CdIn2S4 for efficient photocatalytic hydrogen peroxide generation coupled with selective benzylamine oxidation.

Vacancies engineering has sparked a huge interest in enhancing photocatalytic activity, but monovacancy simultaneously conducts as either electron or hole acceptor and redox reaction, worsening charge transfer and catalytic performance. Here, the concept of electronic inversion has been proposed through the simultaneous introduction of surface oxygen and S vacancies in CdIn2S4 (OSv-CIS). Consequently, under mild conditions, the well-designed OSv-CIS-200 demonstrated a strong rate of N-benzylidenebenzylamine production (2972.07 µmol g-1 h-1) coupled with Hydrogen peroxide (H2O2) synthesis (2362.33 µmol g-1 h-1) (PIH), which is 12.4 times higher than that of CdIn2S4. Density functional theory (DFT) simulation and characterization studies demonstrate that oxygen is introduced into the lattice on the surface of the material, reversing the charge distribution of the S vacancy and enhancing the polarity of the total charge distribution. It not only provides a huge built-in electric field (BEF) for guiding the orientation of the charge transfer, but also acts as a long-distance active site to accelerate reaction and prevent H2O2 decomposition. Our work offers a straightforward connection between the atomic defect and intrinsic properties for designing high-efficiency materials.

Local polarization redistribution in ZnmIn2S3+m for the enhancing synergetic piezo-photocatalytic overall water splitting.

Piezo-photocatalytic water (deuterium oxide) decomposition is a promising strategy for realizing renewable energy, but the manipulation of the polar center remains a big challenge. This study uses a simple low-temperature hydrothermal process to successfully manufacture ZnmIn2Sm+3 (m = 1-3) (ZnIn2S4, Zn2In2S5 and Zn3In2S6). Incorporating both experimental and theoretical analyses, the structural contraction and local polarization of the Zn-S bond in Zn2In2S5 enhance the piezoelectric response and surface charge accumulation, which facilitate charge transfer and reduce the activation energy of water. Remarkably, Zn2In2S5 exhibits excellent piezoelectric photocatalytic total water splitting performance (H2/O2: 4284.72/1967.00 µmol g-1h-1), which is 1.77 times that of photocatalytic performance. Moreover, a significant enhancement in D2O splitting performance can be obtained for the optimized Zn2In2S5. Our work offers valuable insights into the disclosure of local polarization in catalysts for enhancing piezo-photocatalytic overall water splitting.

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.