Ultrathin zinc selenide nanosheet-based intercalation hybrid coupled with CdSe quantum dots showing enhanced photocatalytic CO_(2) reduction

Fabrication of well-designed heterojunctions is an extraordinarily attractive pathway for boosting the photocatalytic activity toward CO_(2) photoreduction.Herein,a novel kind of na nosheet-based intercalation hybrid coupled with CdSe quantum dots(QDs) was successfully fabricated by a facile solvothermal method and served as photocatalyst for full-spectrum-light-driven CO_(2) reduction.Ultra-small CdSe QDs were rationally in-situ introduced and coupled with lamellar ZnSe-intercalation hybrid nanosheet,resulting in the formation of CdSe Q.Ds/ZnSe hybrid heterojunction.Significantly,the concentration of Cd^(2+) could change directly the crystallinity and micromorphology of ZnSe intercalation hybrid,which in turn would impact on the photocatalysis activity.The optimized CdSe QDs/ZnSe hybrid-5 composite demonstrated a considerable CO yield rate of the 25.6 μmol g^(-1) h^(-1) without any additional cocatalysts or sacrificial agents assisting,making it one of the best reported performance toward CO_(2) photoreduction under full-spectrum light.The elevated CO_(2) photoreduction activity could be attributed to the special surface heterojunction,leading to improving the ability of light absorption and promoting the separation/transfer of photogenerated carriers.This present study developed a new strategy for designing inorganic-organic heterojunctions with enhanced photocatalyst for CO_(2) photoreduction and provided an available way to simultaneously mitigate the greenhouse effect and alleviate energy shortage pressure.

Sub-2 nm ultra-thin Bi_(2)O_(2)CO_(3)nanosheets with abundant Bi-O structures toward formic acid electrosynthesis over a wide potential window

The electrocatalytic reduction of CO_(2)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 Bi_(2)O_(2)CO_(3)nanosheets(NSs)with abundant Bi-O structures were in situ synthesized on carbon paper via topological transformation and post-processing.Faraday efficiency of HCOOH(FEHCOOH)reached 90%in a wide potential window(-1.5 to-1.8 V vs.Ag/AgCl).Significantly,excellent FEHCOOH(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 Bi_(2)O_(2)CO_(3)NS was attributed to the abundant Bi-O structures,which was conducive to enhancing the adsorption of CO_(2)^(*)and OCHO^(*)intermediates and can effectively inhibit hydrogen evolution.The excellent performance of Bi_(2)O_(2)CO_(3)NS over a wide potential window could provide new insights for the efficient electrocatalytic conversion of CO_(2).