Enhanced selective photocatalytic CO2 reduction to CO on AuPd decorated Bi2O2.33 nanosheets

Photocatalytic conversion of carbon dioxide (CO2) into valuable fuels addresses pressing needs for renewable energy and carbon neutrality. However, conventional photocatalytic CO2 reduction on semiconductor is usually limited by sluggish electron kinetics, poor efficiency and low product selectivity. Herein, we developed a bimetallic Au/Pd-decorated Bi2O2.33 ultrathin nanosheet photocatalyst for highly selective CO2 reduction to CO under visible light irradiation. Bi2O2.33 nanosheets self-assembled from nanodots serve as ideal supports for Au/ Pd anchoring due to abundant grain boundaries. Systematic characterization reveals the formation of alloyed Au/Pd nanoparticles on the Bi2O2.33 surface, which endowed a superior CO production rate of 436.8 mu mol g-1 h-1 with a selectivity of 96.68 % from CO2 photoreduction. Quantum chemical calculations uncover that plasmonic Au/Pd alloys facilitates interfacial charge transfer and CO2 activation to form the CO-yielding intermediate. This work demonstrates an effective strategy for designing bimetallic plasmonic cocatalysts to optimize the photoreduction selectivity and efficiency of semiconductor photocatalysts.