The electrocatalytic reduction of CO₂ to HCOOH (ERC-HCOOH) is one of the most feasible ways to alleviate energy crisis and solve environmental problems. Nevertheless, it remains a challenge for ERC-HCOOH to maintain excellent activity and selectivity in a wide potential window. Herein, ultra-thin flower-like Bi₂O₂CO₃ nanosheets (NSs) with abundant Bi-O structures were in situ synthesized on carbon paper via topological transformation and post-processing. Faraday efficiency of HCOOH (FE_HCOOH) reached 90% in a wide potential window (−1.5 to −1.8 V vs. Ag/AgCl). Significantly, excellent FE_HCOOH (90%) and current density (47 mA·cm⁻²) were achieved at −1.8 V vs. Ag/AgCl. The X-ray absorption fine structure (XAFS) combined with density functional theory (DFT) calculation demonstrated that the excellent performance of Bi₂O₂CO₃ NS was attributed to the abundant Bi-O structures, which was conducive to enhancing the adsorption of CO₂* and OCHO* intermediates and can effectively inhibit hydrogen evolution. The excellent performance of Bi₂O₂CO₃ NS over a wide potential window could provide new insights for the efficient electrocatalytic conversion of CO₂.

The interfacial compatibility between compact TiO ₂ and perovskite layers is critical for the performance of planar heterojunction perovskite solar cells (PSCs). A compact TiO ₂ film employed as an electron-transport layer (ETL) was modified using 3-aminopropyl trimethoxy silane (APMS) hydrolysate. The power conversion efficiency (PCE) of PSCs composed of an APMS-hydrolysate-modified TiO ₂ layer increased from 13.45 to 15.79%, which was associated with a significant enhancement in the fill factor (FF) from 62.23 to 68.04%. The results indicate that APMS hydrolysate can enhance the wettability of γ-butyrolactone (GBL) on the TiO ₂ surface, form a perfect CH ₃ NH ₃ PbI ₃ film, and increase the recombination resistance at the interface. This work demonstrates a simple but efficient method to improve the TiO ₂ /perovskite interface that can be greatly beneficial for developing high-performance PSCs.

Herein, Zn₃In₂S₆ photocatalyst with (110) exposed facet was prepared by low temperature solvothermal method. On this basis, a highly efficient binary Zn₃In₂S₆/g-C₃N₄ was obtained by low temperature solvothermal method and applied to the degradation of tetracycline (TC). The samples of the preparation were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV–vis diffuse reflection spectroscopy, and photoluminescence spectroscopy. Furthermore, the degradation performance of photocatalysts on TC was investigated under different experimental conditions. Finally, the mechanism of Zn₃In₂S₆/g-C₃N₄ composite material degrading TC is discussed. The results show that Zn₃In₂S₆ and Zn₃In₂S₆/g-C₃N₄ photocatalysts with excellent performance could be successfully prepared at lower temperature. The Zn₃In₂S₆/g-C₃N₄ heterojunction photocatalyst could significantly improve the photocatalytic activity compared with g-C₃N₄. After 150 min of illumination, the efficiency of 80%Zn₃In₂S₆/g-C₃N₄ to degrade TC was 1.35 times that of g-C₃N₄. The improvement of photocatalytic activity was due to the formation of Zn₃In₂S₆/g-C₃N₄ heterojunction, which promoted the transfer of photogenerated electron–holes. The cycle experiment test confirmed that Zn₃In₂S₆/g-C₃N₄ composite material had excellent stability. The free radical capture experiment showed that ·O₂⁻ was the primary active material. This study provides a new strategy for the preparation of photocatalysts with excellent performance at low temperature.