Ag3PO4修饰AgBr纳米线/Ti3C2双异质结复合物的制备及其光催化性能

Synthesis and photocatalytic performance of Ag3PO4-decorated AgBr nanowires/Ti3C2 double-heterostructure composites

摘要:

以十六烷基三甲基溴化铵（Cetyltrimethylammonium Bromide (CTAB)）为模板和溴源，通过添加MXene（Ti3C2），使用共沉淀法制备了Ag3PO4修饰AgBr纳米线/Ti3C2复合催化剂（Ag3PO4-AgBr NW/Ti3C2)）。采用SEM、TEM、XRD、XPS、紫外-可见漫反射光谱、荧光光谱表征和研究了Ag3PO4-AgBr NW/Ti3C2的组织形貌、晶相结构、元素组成状态以及光吸收特性、光生载流子的复合，以罗明丹B（RhB）为目标降解物，考察质量分数1%的Ti3C2分散液添加量对Ag3PO4-AgBr NW/Ti3C2光催化降解RhB的性能影响。结果表明，层状Ti3C2分布在AgBr NW周围，Ag3PO4纳米粒子修饰在两者之上，三种化合物之间形成Z型和肖特基双异质结；质量分数1%的Ti3C2分散液添加量为0.5 g制备的Ag3PO4-AgBr NW/Ti3C2-5具有最佳的光催化降解RhB的性能，30 mg的Ag3PO4-AgBr NW/Ti3C2-5光催化降解30 mL、10 mg /L的RhB溶液，降解率为94.4%；超氧自由基（·O2?）和羟基自由基（·OH）是Ag3PO4-AgBr NW/Ti3C2光催化降解RhB过程中起主要作用的活性物种；AgBr、Ag3PO4、Ti3C2三者之间形成的Z型和肖特基双异质结，增强了光生电子-空穴对（e--h+）的分离效率，提升了Ag3PO4-AgBr NW/Ti3C2光催化性能。

Abstract:

Using Cetyltrimethylammonium Bromide (CTAB) as template and bromine source ?by adding MXene (Ti3C2), Ag3PO4-decorated AgBr nanowires/Ti3C2 (Ag3PO4-AgBr NW/Ti3C2) composites were synthesized by co-precipitation method. The microstructure, crystal structure, elemental composition, optical absorption and photocarrier recombination of Ag3PO4-AgBr NW/Ti3C2 were characterized by SEM, TEM, XRD, XPS, uv-vis diffuse reflectance spectra and fluorescence spectra. The effect of 1% Ti3C2 dispersion on the photocatalytic degradation of Rhodamine B (RhB) by Ag3PO4-AgBr NW/Ti3C2 was investigated. The results showed that the layered-shaped Ti3C2 were dispersed around AgBr nanowires and Ag3PO4 nanoparticles decorated them, thus forming the double-heterostructure of Z-scheme and Schottky. Ag3PO4-AgBr NW/Ti3C2-5 prepared by adding 0.5 g Ti3C2 dispersion with 1% mass fraction had the best performance of photocatalytic degradation of RhB. The photocatalytic degradation rate of RhB (30 mL, 10 mg/l) was 94.4% by Ag3PO4-AgBr NW/Ti3C2-5 (30 mg). The ·OH radicals and ·O2? was the main active species in the photocatalytic degradation of RhB by Ag3PO4-AgBr NW/Ti3C2. The Z-type and Schottky double heterojunction formed between AgBr, Ag3PO4 and Ti3C2 promoted the separation efficiency of photogenerated electron-hole pairs (e-h+) and enhanced the photocatalytic performance of Ag3PO4-AgBr NW/Ti3C2.