Ternary non-noble metal zinc-nickel-cobalt carbonate hydroxide cocatalysts toward highly efficient photoelectrochemical water splitting

摘要

TiO_2 photoanodes have aroused intensive research interest in photoelectrochemical(PEC) water splitting.However, they still suffer from poor electron-hole separation and sluggish oxygen evolution dynamics,leading to the low photoconversion efficiency and limiting commercial application. Here, we designed and fabricated novel ternary non-noble metal carbonate hydroxide(ZNC-CH) nanosheet cocatalysts and integrated them with TiO_2 nanorod arrays as highly efficient photoanodes of PEC cells. Compared with the pristine TiO_2, the photocurrent of photoanode with the optimal amount of ZNC-CH represents3.2 times enhancement, and the onset potential is shifted toward the negative potential direction of62 m V. The remarkable enhancement is attributed to the suppressed carrier recombination and enhanced charge transfer efficiency at the interface of TiO_2, ZNC-CH and electrolyte, which is closely related to the zinc elements modulated intrinsic activity of catalysts. Our results demonstrate that the introduction of multimetallic ZNC-CH cocatalysts onto photoanodes is a promising strategy to improve the PEC efficiency.