Huang Wei, Harnagea Catalin, Tong Xin, Benetti Daniele, Sun Shuhui, Chaker Mohamed, Rosei Federico, Nechache Riad
Centre Énergie, Matériaux et Télécommunications , Institut National de la Recherche Scientifique , 1650, Boulevard Lionel-Boulet , Varennes , Québec J3X 1S2 , Canada.
School of Chemistry and Materials Science , Guizhou Normal University , Guiyang 550001 , People's Republic of China.
ACS Appl Mater Interfaces. 2019 Apr 10;11(14):13185-13193. doi: 10.1021/acsami.8b20998. Epub 2019 Apr 1.
The photoelectric properties of multiferroic double-perovskite BiFeCrO (BFCO), such as above-band gap photovoltages, switchable photocurrents, and bulk photovoltaic effects, have recently been explored for potential applications in solar technology. Here, we report the fabrication of photoelectrodes based on n-type ferroelectric (FE) semiconductor BFCO heterojunctions coated with p-type transparent conducting oxides (TCOs) by pulsed laser deposition and their application for photoelectrochemical (PEC) water oxidation. The photocatalytic properties of the bare BFCO photoanodes can be improved by controlling the FE polarization state. However, the charge recombination as well as the limited charge transfer kinetics in the photoanode/electrolyte cause major energy loss and thus hinder the PEC performance. We show that this problem may be addressed by the deposition of an ultrathin p-type NiO layer on the photoanode to enhance the charge transport kinetics and reduce charge recombination at surface-trapped states for increased surface band bending. A fourfold enhancement of photocurrent density, up to 0.4 mA cm (at +1.23 V vs RHE), a best performance of stability over 4 h, and a high incident photon-to-current efficiency (∼3.7%) were achieved under 1 sun illumination in such p-NiO/n-BFCO heterojunction photoanodes. These studies reveal the optimization of PEC performance by polarization switching of BFCO and the successful achievement of p-TCOs/n-FE heterojunction photoanodes that are able to sustain water oxidation that is stable for many hours.
多铁性双钙钛矿BiFeCrO（BFCO）的光电特性，如带隙以上光电压、可切换光电流和体光伏效应，最近已被探索用于太阳能技术的潜在应用。在此，我们报告了通过脉冲激光沉积制备基于n型铁电（FE）半导体BFCO异质结并涂覆p型透明导电氧化物（TCO）的光电极及其在光电化学（PEC）水氧化中的应用。通过控制FE极化状态可以改善裸BFCO光阳极的光催化性能。然而，光阳极/电解质中的电荷复合以及有限的电荷转移动力学导致了主要的能量损失，从而阻碍了PEC性能。我们表明，通过在光阳极上沉积超薄p型NiO层以增强电荷传输动力学并减少表面陷阱态处的电荷复合以增加表面能带弯曲，可以解决这个问题。在这种p-NiO/n-BFCO异质结光阳极中，在1个太阳光照下实现了光电流密度提高四倍，高达0.4 mA cm²（相对于可逆氢电极在+1.23 V时），4小时以上的最佳稳定性性能以及高入射光子到电流效率（约3.7%）。这些研究揭示了通过BFCO的极化切换优化PEC性能以及成功实现能够维持数小时稳定水氧化的p-TCOs/n-FE异质结光阳极。
