Exceptional co-catalyst free photocatalytic activities of B and Fe co-doped SrTiO3 for CO2 conversion and H2 evolution
Exceptional co-catalyst free photocatalytic activities of B and Fe co-doped SrTiO3 for CO2 conversion and H2 evolution
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B 和 Fe 共掺杂 SrTiO3 对 CO2 转化和 H2 析出具有出色的无助催化剂光催化活性
DOI：
10.1007/s12274-018-2164-z
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发表时间：
2018-12-01
期刊：
影响因子：
9.9
通讯作者：
Luo, Wei
中科院分区：
文献类型：
--
作者：
Humayun, Muhammad;Xu, Lei;Luo, Wei
CO2 应转化为化学燃料，并通过 SrTiO3 (STO) 将 H2O 还原为 H2，因为其相对于 NHE 的负导带位置。本文通过一步溶胶水热法成功制备了一种新型 B 和 Fe 共掺杂 SrTiO3 (B, F-STO) 光催化剂。各种实验证实 B 和 Fe 有效地掺杂到 STO 基体中。硼取代氧阴离子，而铁取代钛阳离子。紫外可见漫反射光谱（UV-vis DRS）和价带X射线光电子能谱（XPS）光谱证实，与B和Fe共掺杂后，STO的带隙从3.4 eV显着降低至1.9 eV。因此，与纯 STO (λ ≤ 360 nm) 相比，B, F-STO 光催化剂表现出更多的吸收 (λ ≤ 650 nm)。此外，从光致发光光谱、荧光光谱和光电化学测量来看，共掺杂 B 和 Fe 显着增强了 STO 中的电荷分离。这导致 CO2 转化为 CH4 以及 CO 和 H2O 分解产生 H2 的紫外-可见光催化活性得到改善。 B、F-STO 产生的 CH4 和 CO 量分别为 ∼ 17.2 和 21 μmol，比 STO（∼ 3.4 μmol CH4 和 5.2 μmol CO）增加了约 5 倍，计算出的 λ = 420 nm 处的量子效率为 ∼ 2.16%。类似地，B、F-STO 产生的 H2 量为 ∼ 61 μmol，比 STO (9 μmol) 提高了约 6.7 倍，计算出的 λ = 420 nm 处的量子效率为 ∼ 2.12%。这项工作为制造用于太阳能燃料生产的高效 SrTiO3 基纳米光催化剂提供了可行的途径。
CO2 should be converted into chemical-fuels, and to reduce H2O to H2 over SrTiO3 (STO) owing to its negative conduction band position vs. NHE. Herein a novel B and Fe co-doped SrTiO3 (B, F-STO) photocatalyst was successfully fabricated via a single-step sol-hydrothermal process. Various experiments confirmed that B and Fe are effectively doped into the STO matrix. Boron substituted oxygen anions, while Fe substituted Ti cations. UV–visible diffuse reflectance spectra (UV–vis DRS) and valence-band X-ray photoelectron spectroscopy (XPS) spectra confirmed that the band gap of STO significantly reduced from 3.4 to 1.9 eV upon co-doping with B and Fe. Hence, the B, F-STO photocatalyst exhibits more absorption (λ ≤ 650 nm) compared to pure STO (λ ≤ 360 nm). Further, from photoluminescence spectra, fluorescence spectra, and photoelectrochemical measurements, charge separation in STO is considerably enhanced by co-doping B and Fe. This resulted in the improved UV–vis light catalytic activities for CO2 conversion to CH4 and CO and H2O splitting to evolve H2. The amounts of CH4 and CO produced over B, F-STO are ∼ 17.2 and 21 μmol, respectively, about 5-fold enhanced compared to that of STO (∼ 3.4 μmol CH4 and 5.2 μmol CO), and the calculated quantum efficiency at λ = 420 nm is ∼ 2.16%. Similarly, the amount of H2 produced over B, F-STO is ∼ 61 μmol, about 6.7-fold enhanced compared to that over STO (9 μmol), and the calculated quantum efficiency at λ = 420 nm is ∼ 2.12%. This work provides feasible routes to fabricate highly efficient SrTiO3-based nanophotocatalysts for solar-fuel production.