Facile synthesis of dual Z-scheme g-C3N4/Ag3PO4/AgI composite photocatalysts with enhanced performance for the degradation of a typical neonicotinoid pesticide
Facile synthesis of dual Z-scheme g-C3N4/Ag3PO4/AgI composite photocatalysts with enhanced performance for the degradation of a typical neonicotinoid pesticide
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DOI：
10.1016/j.apcatb.2019.118395
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发表时间：
2020-07
影响因子：
22.1
通讯作者：
M. Tang;Y. Ao;Chao Wang;Peifang Wang
中科院分区：
文献类型：
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作者：
M. Tang;Y. Ao;Chao Wang;Peifang Wang
以Z型Ag 3 PO 4/g-C3 N4为原料，采用原位离子交换法制备了双Z型光催化剂AgI/Ag 3 PO 4/g-C3 N4（AAC）。该双Z型光催化剂对烯啶虫胺（NTP）的降解活性高于纯g-C3 N4、Ag 3 PO 4和AgI及其二元复合物。最佳样品的NTP降解表观速率常数（0.76 min-1）分别约为g-C3 N4、Ag 3 PO 4和AgI的16.2、2.4和2.9倍。光致发光谱和瞬态光电流响应结果表明，AAC光生电子和空穴的分离效率显著提高，有利于提高其光催化活性。活性物种捕获实验和电子自旋共振谱表明，超氧自由基和空穴是NTP降解的主要活性物质，证明了Z-图式结构的形成。此外，基于高效液相色谱-质谱联用技术的结果，推测了NTP的可能降解途径。
A dual Z-scheme photocatalyst AgI/Ag3PO4/g-C3N4(AAC) is prepared by an in-situ ion exchange method from Z-scheme Ag3PO4/g-C3N4. This dual Z-scheme photocatalyst exhibits higher activity for the degradation of nitenpyram (NTP) than pure g-C3N4, Ag3PO4and AgI and their binary composites. The apparent rate constant of NTP degradation for the optimal sample (0.76 min−1) is about 16.2, 2.4 and 2.9 times as that of g-C3N4, Ag3PO4and AgI, respectively. The results of photoluminescence spectroscopy and transient photocurrent response show that the separation efficiency of photogenerated electrons and holes for AAC is significantly improved, which is beneficial to improve its photocatalytic activity. Active species capture experiments and electron spin resonance spectra show that superoxide radicals and holes are the main active substances for NTP degradation and prove the formation of Z-scheme structure. In addition, basing on the results of high-performance liquid chromatography mass spectrometry, a possible degradation pathway of NTP is deduced.