School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Rd., Shanghai 200240, PR China.
Nanoscale. 2018 Oct 4;10(38):18378-18386. doi: 10.1039/c8nr06342g.
In this paper, a high-performance BiVO4 photoanode deposited with serial hole transfer layers was fabricated for photoelectrochemical (PEC) water splitting in order to overcome the shortcomings of pure BiVO4 electrodes in terms of poor charge transport properties and undesirable surface water oxidation kinetics. The hole transfer layer of Fe2O3 was first deposited on the surface of pure BiVO4 to promote the hole transfer from the bulk of the semiconductor to the electrode surface (bulk/surface transfer process), and then the hole transfer layer of NiOOH/FeOOH was deposited on the surface to improve the hole transfer from the electrode surface to the electrolyte (surface/electrolyte transfer process). The results showed a remarkable improvement in PEC water splitting performance for the NiOOH/FeOOH/Fe2O3/BiVO4 photoanode. The photocurrent was up to 2.24 mA cm-2 at 1.23 V vs. RHE, which was about 2.95 times that of the pristine BiVO4 photoanode. Meanwhile, the charge transport efficiencies in the bulk (ηbulk) and the surface (ηsurface) were enhanced by 1.63 and 2.62 times compared to those of the BiVO4 photoanode at 1.23 V vs. RHE, respectively. In addition, the novel photoanode was assembled with a commercial silicon PVC for self-bias PEC water splitting, and a stable photocurrent density of ∼2.60 mA cm-2, corresponding to a ∼3.2% STH conversion efficiency, was achieved spontaneously. Our study provided a more efficient serial hole transfer strategy for achieving a BiVO4 photoanode with enhanced PEC water splitting.
本文制备了一种具有串联空穴传输层的高性能 BiVO4 光阳极，用于光电化学（PEC）水分解，以克服纯 BiVO4 电极在电荷传输性能差和表面水氧化动力学不理想方面的缺点。首先在纯 BiVO4 表面沉积 Fe2O3 空穴传输层，以促进空穴从半导体体相转移到电极表面（体相/表面转移过程），然后在表面沉积 NiOOH/FeOOH 空穴传输层，以提高空穴从电极表面到电解质的转移效率（表面/电解质转移过程）。结果表明，NiOOH/FeOOH/Fe2O3/BiVO4 光阳极的 PEC 水分解性能得到显著提高。在 1.23 V vs. RHE 时，光电流达到 2.24 mA cm-2，约为原始 BiVO4 光阳极的 2.95 倍。同时，与 BiVO4 光阳极相比，在 1.23 V vs. RHE 时，体相（ηbulk）和表面（ηsurface）的电荷传输效率分别提高了 1.63 倍和 2.62 倍。此外，将新型光阳极与商业硅 PVC 组装进行自偏压 PEC 水分解，自发实现了约 2.60 mA cm-2 的稳定光电流密度，对应约 3.2%的 STH 转换效率。本研究为实现具有增强 PEC 水分解性能的 BiVO4 光阳极提供了一种更有效的串联空穴传输策略。
