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

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.

DC sputter deposited TiO2 layers on FTO: towards a maximum photoelectrochemical response of photoanodes

“…In view of the electrode geometry, typical IPCE data (acquired under moderate anodic bias and in the UV range) are 5-20% for compact films [9,21,26]. For 3D structures, typical IPCE values are reported as 15-35% for nanotubes [9][10][11]21], 40-65% for nanoflakes [18,27], 15-30% for nanowires [1,22], and 2-8% for compacted nanoparticle photoanodes [9,29,30]. The better IPCE performance for the 3D structures often is ascribed to the higher surface area of the corresponding geometries.…”