Ti(IV)-石墨烯双助剂协同效应增强钨酸铋光催化性能

doi:10.15541/jim20160345

摘要/Abstract

摘要：

助剂修饰是促进光生电子和空穴分离的有效途径。采用新型无定型Ti(IV)空穴助剂与高电子传输率的还原石墨烯(rGO)电子助剂相结合, 以水热-浸渍沉积法合成Ti(IV)和rGO共修饰的高效片状钨酸铋(Ti(IV)-rGO/Bi₂WO₆)可见光光催化剂。结果表明, 与单独Bi₂WO₆相比, 助剂Ti(IV)或rGO修饰的Bi₂WO₆可见光光催化降解甲基橙(MO)性能增强。双助剂共修饰的Bi₂WO₆光催化剂光催化活性更高, 当Ti(IV)含量为5wt%时, 双助剂共修饰的Bi₂WO₆光催化剂性能最佳, 光催化速率常数达2.2×10^-2 min^-1, 是纯Bi₂WO₆的88倍。光催化性能增强主要归因于新型Ti(IV)空穴助剂与rGO电子助剂的协同作用, 即Ti(IV)快速转移光生空穴, 同时rGO快速传递并转移电子。本文有望为新型助剂修饰光催化材料研究提供新思路。

关键词: 钨酸铋, 石墨烯, 无定型Ti(IV)空穴助剂, 可见光光催化性能

Abstract:

Cocatalyst modification is an effective way to promote the separation of photogenerated electron-hole pairs. The reduced graphene oxide (rGO) with high electron transfer rate and the amorphous Ti(IV) compounds as hole cocatalyst were loaded on the surface of highly-efficient and flake-like Bi₂WO₆ nanoparticles by a hydrothermal-impregnation method to prepare Ti(IV)-rGO/Bi₂WO₆ visible-light-driven photocatalyst. It was found that the Ti(IV) and rGO single-cocatalyst modified Bi₂WO₆ exhibited an enhanced photocatalytic activity and dual-cocatalyst modified Bi₂WO₆ photocatalyst showed higher photocatalytic performance than single-cocatalyst modified Bi₂WO₆. When the amount of Ti(IV) was 5wt%, the photocatalytic rate constant of Ti(IV)-rGO/Bi₂WO₆photocatalyst reached 2.2×10^-2 min^-1, which was 88-fold higher than that of bare Bi₂WO₆. The enhancement of photocatalytic performance mainly depends on the synergistic effect of novel Ti(IV)-hole cocatalyst and rGO-electron cocatalyst, namely, Ti(IV) compounds rapidly transfer the photogenerated holes, while rGO rapidly capture the photogenerated electrons. The present amorphous Ti(IV) and rGO cocatalysts can be widely applied in the design and development of highly efficient cocatalyst-modified photocatalytic materials.

Key words: Bi2WO6, graphene, amorphous Ti(IV) hole-cocatalyst, visible-light photocatalytic activity.

中图分类号:

O643

宋佳, 徐瑛, 貊艳平, 李永安. Ti(IV)-石墨烯双助剂协同效应增强钨酸铋光催化性能[J]. 无机材料学报, 2017, 32(3): 269-274.

SONG Jia, XU Ying, MO Yan-Ping, LI Yong-An. Enhanced Photocatalytic Activity of Bi₂WO₆ by the Synergistic Action of Ti(IV) and Graphene Bi-cocatalysts[J]. Journal of Inorganic Materials, 2017, 32(3): 269-274.

图/表 10

图1 助剂负载的各样品合成示意图

Fig. 1 Schematic diagram illustrating the preparation of various samples(a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)-rGO/ Bi2WO6

图2 各样品的XRD图谱

Fig. 2 XRD patterns of different samples(a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)-rGO/ Bi2WO6; (e) Ti(IV)

图3 样品的FESEM照片和EDX图谱

Fig. 3 FESEM images and EDX results (insert) of different samples(a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)-rGO/Bi2WO6

图4 各样品的拉曼图谱

Fig. 4 Raman spectra of (a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)-rGO/Bi2WO6; (e) rGO; (f) GO

图5 不同样品的红外图谱

Fig. 5 FTIR spectra of various samples(a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)-rGO/Bi2 WO6; (e) rGO; (f) GO

图6 不同样品的紫外可见漫反射图谱

Fig. 6 UV-vis DRS of different samples(a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)-rGO/Bi2 WO6 and Energy band diagram of Bi2WO6(insert)

图7 不同样品的光催化性能图

Fig. 7 Photocatalytic performance of the decomposition of MO by different samples(a) Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) rGO/Bi2WO6; (d) Ti(IV)(1%)- rGO/Bi2WO6; (e) Ti(IV)(3%)-rGO/Bi2WO6; (f) Ti(IV)-rGO/Bi2WO6; (g) Ti(IV)(7%)-rGO/Bi2WO6

图8 Ti(IV)-rGO/Bi2WO6光催化降解MO的循环性能

Fig. 8 Recycled photocatalytic performance of Ti(IV)-rGO/ Bi2WO6 for the decomposition of MO

图9 Ti(IV)-rGO/Bi2WO6光催化性能及降解苯酚的循环性能

Fig. 9 The photocatalytic performance of Ti(IV)-rGO/Bi2 WO6 for the decomposition of MO and phenol and recycled performance for the degradation of phenol(insert)

图10 助剂负载的Bi2WO6样品的光催化机理图

Fig. 10 Photocatalytic mechanism of (a) rGO/Bi2WO6; (b) Ti(IV)/Bi2WO6; (c) Ti(IV)-rGO/Bi2WO6

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