rGO modified in situ transformed Bi2S3/BiVO4 heterostructure for photoelectrochemical water oxidation

Based on the advantages of low cost, photoelectrochemical stability and non-toxicity of BiVO 4 , we prepared BiVO 4 photoanode by the classical electrodeposition method and grew Bi 2 S 3 in situ relying on its own bismuth source to construct a type-II heterojunction. The BiVO 4 /Bi 2 S 3 /rGO ternary photoanode exhibits excellent PEC performance under the synergistic effect of rGO modification and heterojunction. The results show that the photocurrent density of the BiVO 4 /Bi 2 S 3 /rGO photoanode at 1.23 V vs RHE reaches 2.40 mA·cm -2 , which is 3.4 times higher than BiVO 4 (0.70 mA·cm -2 ), the onset potential is negatively shifted by 140 mV compared with BiVO 4 , and the highest IPCE and ABPE efficiencies reach 39.68% and 0.24%, respectively, while the charge transfer resistance R ct was reduced to 163 Ω. The enhancement is attributed to the construction of the heterojunction and its synergistic effect with rGO, which is from extending the visible light absorption of the photoanode, promoting the effective separation of carriers, and accelerating of interface charge transfer as well as providing more active sites for water oxidation.