Photoelectrochemical properties of TiO2/g-C3N4 composited electrodes fabricated by a co-electrodeposited method

Abstract

Abstract Graphitic carbon nitride (g-C3N4) usually shows a low photoelectrochemical (PEC) performance due to its poor conductivity. To improve the transfer of charge carriers generated by g-C3N4, a TiO2/g-C3N4 composite photoanode was prepared by a facile co-electrodeposition method. The composite photoelectrodes exhibit an improved PEC performance compared to TiO2 and g-C3N4. The PEC performance was optimized by varying the mass ratio of TiO2 to g-C3N4, and a ratio of 1:1 gave the best photocurrent density of 1.81 mA cm−2, which is 2.27 times larger than that of the pure TiO2 photoanode under full-arc xenon light. Furthermore, compared with pure g-C3N4, the photocurrent density is greatly improved. The incident photocurrent efficiency reached 4.14% under irradiation with 365 nm monochromatic light. TiO2/g-C3N4 exhibits a stable photocurrent density in a PEC reaction over 2 h. The enhanced PEC performance is attributed to the synergism between TiO2 and g-C3N4 semiconductors, which improves the interfacial charge transfer and inhibits the photogenerated electron–hole pair recombination.