Enhanced solar light driven activity of p-n heterojunction for water oxidation induced by deposition of Cu2O on Bi2O3 microplates

Abstract As an important half reaction in solar-driven water splitting, it is more challenging to develop low-cost and highly efficient photocatalysts for water oxidation. The enhancement of sunlight harvesting and inhibition of charge-carrier recombination are keys to fabricating efficient semiconductor-based photocatalysts for energy conversion from solar light to chemicals. Herein, we reported highly dispersive Cu 2 O/Bi 2 O 3 composites prepared by a facile and benign synthetic route, where n -type Bi 2 O 3 microplates and nano-sized p -type Cu 2 O were coupled together to construct heterojunctions to improve the transportation efficiency of photoinduced charge carriers, benefited from the intimate interactions at the interfaces between Bi 2 O 3 and Cu 2 O. The electrochemical properties of charge-transportation and population of charge carriers were investigated in the heterojunctions. The hybrid materials exhibit both enhanced photocatalytic performances in water oxidation and photodegradation of dyes compared with sole Bi 2 O 3 or Cu 2 O under artificial solar light irradiation. The initial O 2 evolution rate of the heterojunction system is 1.4- and 8-fold higher than the pure Bi 2 O 3 and Cu 2 O, respectively. This study provides new protocols for synthesizing novel hybrid materials with insights into heterojunction-based photocatalysis for green energy production and wastewater purification.