Zhang Zhujun, Nagashima Hiroki, Tachikawa Takashi
Department of Chemistry, Graduate School of Science, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan.
Molecular Photoscience Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan.
Angew Chem Int Ed Engl. 2020 Jun 2;59(23):9047-9054. doi: 10.1002/anie.202001919. Epub 2020 Apr 30.
Significant charge recombination that is difficult to suppress limits the practical applications of hematite (α-Fe O ) for photoelectrochemical water splitting. In this study, Ti-modified hematite mesocrystal superstructures assembled from highly oriented tiny nanoparticle (NP) subunits with sizes of ca. 5 nm were developed to achieve the highest photocurrent density (4.3 mA cm at 1.23 V vs. RHE) ever reported for hematite-based photoanodes under back illumination. Owing to rich interfacial oxygen vacancies yielding an exceedingly high carrier density of 4.1×10 cm for super bulk conductivity in the electrode and a large proportion of ultra-narrow depletion layers (<1 nm) inside the mesoporous film for significantly improved hole collection efficiency, a boosting of multihole water oxidation with very low activation energy (E =44 meV) was realized.
难以抑制的显著电荷复合限制了赤铁矿（α-Fe₂O₃）在光电化学水分解中的实际应用。在本研究中，开发了由尺寸约为5 nm的高度取向的微小纳米颗粒（NP）亚基组装而成的Ti改性赤铁矿介晶超结构，以实现背照光下赤铁矿基光阳极所报道的最高光电流密度（在1.23 V vs. RHE下为4.3 mA cm²）。由于丰富的界面氧空位在电极中产生了高达4.1×10²¹ cm⁻³的载流子密度以实现超体电导率，并且介孔膜内有很大比例的超窄耗尽层（<1 nm）以显著提高空穴收集效率，从而实现了具有极低活化能（Ea =44 meV）的多空穴水氧化增强。
