Solar-driven CO2 reduction to solar fuel is an effective way to deal with the greenhouse effect and energy crisis. A one-step hydrothermal method was used to synthesize Bi4Ti3O12 / SrTiO3 composite photocatalysts. The heterogeneous structure formed by intimate contact was observed between SrTiO3 (STO) nanoparticles and Bi4Ti3O12 (BTO) nanoplates, achieving an enhanced photocatalytic CO2 reduction yield of CO (13.37 μmol / g) that was 5.74-fold that of pure STO (2.33 μmol / g), with a high yield of CH4 (1.55 μmol / g). Characterizations of phase composition, morphology, and optical/electrochemical properties were applied to prove the heterojunction structure and its role in improving the photocatalytic performance. X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy tests demonstrate that electrons transfer from STO to BTO and result in the generation of an internal electron field between the two phases. Consequently, a direct Z-scheme system was formed: photoelectrons in the conduction band of BTO transferred to the valence band of STO to recombine with the holes thus spatially separated the photogenerated electron–hole pairs while enabling the photocatalyst to achieve the maximum reduction and oxidation capability. The catalyst structure system proposed here may bring new ideas for the development of titanate-based photocatalysts with high CO2 reduction activity.

中文翻译：

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直接Z方案Bi ₄ Ti ₃ O ₁₂ / SrTiO ₃光催化剂对CO ₂还原为太阳能的光催化性能增强

由太阳能驱动的将二氧化碳减少为太阳能燃料是应对温室效应和能源危机的有效途径。采用一步水热法合成了Bi4Ti3O12 / SrTiO3复合光催化剂。观察到SrTiO3（STO）纳米颗粒和Bi4Ti3O12（BTO）纳米板之间紧密接触形成的异质结构，实现了CO（13.37μmol/ g）的光催化CO2还原产率的提高，是纯STO（2.33μmol/ g）的5.74倍。 g），CH4的收率高（1.55μmol/ g）。相组成，形态和光学/电化学性质的表征被用来证明异质结结构及其在提高光催化性能中的作用。X射线光电子能谱和紫外光电子能谱测试表明，电子从STO转移到BTO，并导致两相之间产生内部电子场。因此，形成了直接的Z方案系统：BTO导带中的光电子转移到STO的价带以与空穴复合，从而在空间上分隔了光生电子-空穴对，同时使光催化剂能够实现最大程度的还原和氧化能力。本文提出的催化剂结构体系可能为开发具有高CO 2还原活性的钛酸酯基光催化剂带来新的思路。BTO导带中的光电子转移到STO的价带以与空穴复合，因此在空间上分离了光生电子-空穴对，同时使光催化剂能够实现最大程度的还原和氧化能力。本文提出的催化剂结构体系可能为开发具有高CO 2还原活性的钛酸酯基光催化剂带来新的思路。BTO导带中的光电子转移到STO的价带以与空穴复合，因此在空间上分离了光生电子-空穴对，同时使光催化剂能够实现最大程度的还原和氧化能力。本文提出的催化剂结构体系可能为开发具有高CO 2还原活性的钛酸酯基光催化剂带来新的思路。