功能模板导向合成介孔三氧化钨及其光电化学性能

摘要/Abstract

摘要： 以钨酸(H₂WO₄)为钨前驱体,十二烷胺(DDA)为模板剂,利用模板剂的结构导向功能,合成了比表面积为57.3 m²·g^-1的介孔三氧化钨(DDA-WO₃),是未用DDA制备的非介孔WO₃(H₂WO₄-WO₃)的2.35倍。X射线衍射(XRD)结果表明,400 ℃下煅烧的DDA-WO₃是具有单斜晶型结晶孔壁的无序介孔结构。此外,400~550 ℃下煅烧的DDA-WO₃的结晶度均高于同条件的H₂WO₄-WO₃。400 ℃下的DDA-WO₃/FTO(掺氟氧化锡)在1.0 V的Ag/AgCl偏压作用下,可以产生0.18 mA·cm^-2的饱和光电流,是H₂WO₄-WO₃/FTO(0.06 mA·cm^-2)的3倍。增强的光电化学(PEC)活性主要因为DDA-WO₃/FTO的大表面积降低了低结晶度对PEC性能的不利影响,成为影响PEC活性的主要因素。500 ℃煅烧导致了DDA-WO₃/FTO介孔结构的坍塌,但高的结晶度仍然保持其优越的PEC催化活性。

关键词: 介孔结构, 模板, 三氧化钨, 光阳极, 光电化学性能

Abstract: Mesoporous tungsten trioxide (DDA-WO₃) was prepared using tungstic acid (H₂WO₄) as a tungsten precursor, dodecylamine (DDA) as a surfactant template which has structure guiding function. The specific surface area (57.3 m²·g^-1) of DDA-WO₃ was 2.35 times of 24.5 m²·g^-1for WO₃ (H₂WO₄-WO₃) prepared without DDA. X-ray diffraction (XRD) result of the DDA-WO₃ calcined at 400 ℃ indicates that a crystalline framework with disordered arrangement of pores. The crystallinity of DDA-WO₃ calcined at 400~550 ℃ is higher than each of H₂WO₄-WO₃. DDA-WO₃/FTO (SnO₂∶F) calcined at 400 ℃ generates photoanodic current density of 0.18 mA·cm^-2 at 1.0 V versus Ag/AgCl, which is about 3 times higher than that of the H₂WO₄-WO₃/FTO(0.06 mA·cm^-2). The enhanced photoelectrochemical (PEC) performance of DDA-WO₃/FTO suggests that the higher specific surface area of mesoporous structure is a dominant factor for the PEC performance rather than insufficient crystallinity. DDA-WO₃/FTO calcined at 500 ℃ still exhibites excellent PEC performance than H₂WO₄-WO₃/FTO due to higher crystallinity, although the degradation of the mesostructure at higher temperature.

Key words: mesoporous structure, template, WO₃, photoanode, phototelectrochemical performance

中图分类号:

李东, 高彩云. 功能模板导向合成介孔三氧化钨及其光电化学性能[J]. 人工晶体学报, 2020, 49(12): 2350-2357.

LI Dong, GAO Caiyun. Synthesis by Functional-Template Induced Methodology and Photoelectrochemical Performance of Mesoporous Tungsten Trioxide[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2020, 49(12): 2350-2357.

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