上海科技大学知识管理系统

Photocatalytic conversion of carbon dioxide (CO2) is a promising strategy for both renewable solar energy storage and carbon emission reduction. Forming multicarbon products in CO2 photocatalytic reduction remains very difficult, due to the kinetic barriers of C-C coupling. In this study, we introduce surface pentavalent tungstic (W5+) species in nonstoichiometric tungsten oxides via carbothermal reduction of commercial WO3 powder, achieving photocatalytic CO2 conversion with an aldehyde selectivity of 35% at a total normal CO2 conversion rate of 1.8 mu mol.g(cat)(-1).h(-1). The as-prepared nonstoichiometric tungsten oxides exhibit improved band structures and electron transport properties, and the W5+ surface species with oxygen vacancies play a pivotal role in facilitating C-C coupling of key intermediates. In-depth carbothermal reduction at an elevated temperature (880 degrees C) delivers more tetravalent W4+ species, decreasing the CO and aldehyde production rates. This work provides fundamental information to facilitate C-C coupling in CO2 photoreduction via the introduction of surface active species.