Wu Hao, Qu Songying, Ng Yun Hau
Macau Institute of Materials Science and Engineering (MIMSE), Faculty of Innovation Engineering, Macau University of Science and Technology, Taipa 999078, Macau SAR.
School of Energy and Environment, City University of Hong Kong, Kowloon Tong 999077, Hong Kong SAR.
J Am Chem Soc. 2025 Apr 2;147(13):10829-10833. doi: 10.1021/jacs.4c18733. Epub 2025 Mar 24.
Solar-driven one-step-excitation overall water splitting is one of the most straightforward ways of achieving scalable solar hydrogen production. Despite its advantage in visible-light response and stability, the pristine bismuth vanadate (BiVO) alone is not capable of achieving overall water splitting due to its conduction band energy level being insufficient for the proton reduction reaction, further limited by the severe charge recombination. Here, we demonstrate the three-dimensionally ordered macroporous BiVO with a carefully enlarged bandgap of 2.58 eV and a conduction band energy of -0.49 eV versus normal hydrogen electrode at pH 7.0. On loading Rh/CrO as a hydrogen evolution cocatalyst, the stochiometric evolution of hydrogen and oxygen in a recyclable manner is accomplished under visible light with an apparent quantum yield of 0.47% at 400 nm. Further study by Kelvin probe force microscopy reveals an intensified internal electric field with a downward band bending from the interconnection part to the internal wall of the periodic porous structure upon loading the cocatalysts. Our findings transform BiVO from a typical water oxidation photocatalyst into a new paradigm for single-component photocatalysts for overall water splitting.
太阳能驱动的一步激发全水分解是实现可扩展太阳能制氢的最直接方法之一。尽管原始钒酸铋（BiVO）在可见光响应和稳定性方面具有优势，但由于其导带能级不足以进行质子还原反应，且受严重的电荷复合进一步限制，仅靠它本身无法实现全水分解。在此，我们展示了具有精心扩大的2.58 eV带隙和相对于pH 7.0标准氢电极-0.49 eV导带能量的三维有序大孔BiVO。在负载Rh/CrO作为析氢共催化剂时，在可见光下以可循环的方式实现了氢气和氧气的化学计量演化，在400 nm处的表观量子产率为0.47%。通过开尔文探针力显微镜的进一步研究表明，负载共催化剂后，从周期性多孔结构的互连部分到内壁出现了带向下弯曲的增强内电场。我们的发现将BiVO从一种典型的水氧化光催化剂转变为用于全水分解的单组分光催化剂的新范例。
