BiVO₄-based photoanode is one of the most promising photoanodes for photoelectrocatalytic water splitting. However, the serious problem of interface charge recombination limits its further development. Here, a Mo:BiVO₄/NiO_x/CPF-TCzB/NiCoBi photoanode is constructed with double hole transport layer and an energy level gradient to achieve an effective photo-generated holes extraction and accumulation at the surface electrocatalyst. The conjugated polycarbazole framework CPF-TCzB is used as hole transport layer to eliminate the charge recombination center between Mo:BiVO₄ and NiCoBi electrocatalyst and realize the extraction and storage of photo-generated hole; NiO_x nanoparticles are further inserted between Mo:BiVO₄ and CPF-TCzB to form a gradient energy level, eliminating the energy level barrier and optimizing band alignment. As a result, Mo:BiVO₄/NiO_x/CPF-TCzB/NiCoBi achieves a much higher photocurrent densities of 3.14 mA cm⁻² than that of Mo:BiVO₄ (0.42 mA cm⁻²) at 0.6 V versus RHE. This work provides an specific way to adjust the band structure of BiVO₄-based photoanodes and realize efficient hole extraction and storage for PEC water splitting.

中文翻译：

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双空穴传输层异质结和能带对准设计的 Mo:BiVO4 光电阳极可实现高效水分解


BiVO ₄ 基光阳极是光电催化水分解最有前途的光阳极之一。然而，严重的界面电荷复合问题限制了其进一步发展。这里，Mo:BiVO ₄ /NiO _x /CPF-TCzB/NiCoBi 光阳极构造有双空穴传输层和能级梯度，以实现有效的光生空穴提取以及在表面电催化剂上的积累。以共轭聚咔唑骨架CPF-TCzB作为空穴传输层，消除Mo:BiVO ₄ 与NiCoBi电催化剂之间的电荷复合中心，实现光生空穴的提取和存储； NiO _x 纳米粒子进一步插入 Mo:BiVO ₄ 和 CPF-TCzB 之间，形成梯度能级，消除能级势垒并优化能带排列。结果，Mo:BiVO ₄ /NiO _x /CPF-TCzB/NiCoBi 实现了比 Mo 高得多的光电流密度 3.14 mA cm ⁻² ：BiVO ₄ (0.42 mA cm ⁻² )，相对于 RHE，电压为 0.6 V。这项工作提供了一种调整BiVO ₄ 基光阳极能带结构并实现PEC水分解的高效空穴提取和存储的具体方法。