Polyaniline/g-C 3 N 4 /Bi 2 O 3 /Ti photoanode for visible light responsive photocatalytic fuel cell degradation of rhodamine B and electricity generation

In order to develop efficient photoanode to improve the performance of visible light responsive photocatalytic fuel cell (PFC), in this work, polyaniline/g-C 3 N 4 /Bi 2 O 3 /Ti photoanode was successfully prepared using silica-sol drop coating method, and assembled with Cu cathode to construct PFC to decompose rhodamine B and generate electricity simultaneously. The degradation rate, maximum photocurrent density and maximum power density of this PFC were 91.23%, 0.086 mA cm −2 and 4.78 μW cm −2, respectively, which were 1.4 and 1.8 times, 2.4 and 4.5 times, and 1.9 and 7.3 times those of the corresponding values of the PFCs with g-C 3 N 4 /Bi 2 O 3 /Ti and Bi 2 O 3 /Ti photoanodes, respectively. This is attributed to the type II heterojunction structure formed among polyaniline, g-C 3 N 4 and Bi 2 O 3 in the polyaniline/g-C 3 N 4 /Bi 2 O 3 /Ti photoanode. Among them, polyaniline has π-π conjugated structure, which can rapidly transfer the electronic charge between g-C 3 N 4 and Bi 2 O 3, thus enhancing the separation efficiency of photo-generated e − -h + pairs spatially and reducing their recombination, extending the visible light response wavelength of the photocatalyst, and finally improving its photocatalytic properties. This study can provide significant reference for the research of Bi 2 O 3 -based visible light responsive PFC.