在現今社會快速的發展之下，能源短缺與環境汙染的相關議題漸漸地浮上檯面，因此利用太陽能進行光電化學水分解也成為了廣為人知的研究主題。而BiVO4光陽極已被廣泛用於光電化學水分解的理想材料，但因材料本身有嚴重的電子電洞再結合現象，以及緩慢的與水反應動力學，因此本研究致力於開發一個新穎且有效的觸媒，以改善BiVO4光陽極之光電化學水分解效率。
本研究利用簡便且快速的電沉積法製備出鋅鈷釩三元素之層狀雙氫氧化物(ZnCoV-LDH)，並將其沉積於BiVO4表面上，作為一種新的助催化劑，以提升BiVO4光陽極的光電化學水分解效率。以鹼性的四硼酸鈉為電解液，於1.23 V vs. RHE之下，經改善後的光陽極展現出2.54 mA/cm2的光電流表現，為原始BiVO4光陽極的三倍，且起始電位也向陰極偏移300 mV。此外還發現ZnCoV-LDH將原本BiVO4僅有的27 %電洞注入效率提升至82 %。更值得一提的是，此觸媒在長時間電解反應中展現出優越的穩定性。證明此助催化劑除了能降低動力學屏障以外，更藉由促進電荷分離以抑制被激發後的電荷重組現象，達到穩定BiVO4光陽極的效果，藉此提高水分解效率。此研究不僅提出新穎且有效的助催化劑，更提供一個快速簡便製備氫氧化物材料的方法。

Bismuth vanadate has been extensively studied as an ideal photoanode material for solar-driven photoelectrochemical (PEC) water splitting but it still suffers from the severe electron-hole recombination and sluggish water oxidation kinetics thus cause low efficiency of PEC water splitting. Therefore, this study is dedicated to explore a new and efficient oxygen evolution cocatalysts for boosting photoelectrochemical (PEC) water splitting of BiVO4 photoanode.
Herein, a novel ZnCoV layered double hydroxide (ZnCoV-LDH) has been controllably prepared by a facile and rapid electrodeposition method for as a new co-catalyst for enhancing photoelectrochemical water oxidation of BiVO4 photoanode. Upon incorporating ZnCoV-LDH on the surface of BiVO4, the modified photoanode exhibits photocurrent density of 2.54 mA cm−2 (at 1.23 V versus reversible hydrogen electrode), which is 3 times higher than that of bare BiVO4 and 300 mV cathodic shift in onset potential. In addition, ZnCoV-LDH was also found to boost the hole injection efficiency of BiVO4 from 27% up to approximately 82%. More interestingly, the composite electrode demonstrates an reasonably good durability which attain a stable photocurrent density without significant decay during water splitting process. The significant improvement in photocurrent density, hole collection efficiency as well as durability can be ascribled to the fact that ZnCoV-LDH is acting as efficient oxygen evolution catalyst, thereby promotes the separation of photogenerated charges to suppress the recombination phenomenon, and stabilize BiVO4 photoelectrode for enhancing efficiency of water splitting. This work provides not only a demonstration of a novel and promising co-catalyst for PEC water splitting, but also a facile method for rationally designing other hydroxide-based materials.

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