n-p异质结型Ag3PO4-LaFeO3/EB复合材料的制备及其光催化性能

以剥离膨润土(EB)为载体,采用原位沉积-沉淀法制备出n-p异质结型Ag3PO4-LaFeO3/EB-40％(40％为LaFeO3的掺杂量,以Ag3PO4和LaFeO3的质量计,下同)复合光催化剂.通过XRD、TEM、XPS、UV-Vis DRS、BET、EIS、瞬态光电流对材料的形貌、晶形结构、光吸收性能、比表面积及光电化学特性进行了表征分析.结果表明,Ag3PO4与LaFeO3形成了紧密的n-p异质结并均匀分散在EB表面,提高了材料对可见光的利用,拓宽了Ag3PO4的光吸收范围,有效促进了光生电子-空穴对的分离.以可见光降解模拟苯酚废水来评价材料的光催化性能,发现Ag3PO4-LaFeO3/EB-40％的速率常数约为纯Ag3PO4的4.2倍,在中性条件下苯酚的降解率约为97.0％,且循环4次后苯酚的降解率仍可达81.6％.

Preparation and Performance of n-p heterojunction Ag3PO4-LaFeO3 supported EB nano-photocatalyst

N-p heterojunction Ag3PO4-LaFeO3/EB-40% photocatalyst was prepared by in-situ deposition-precipitation method using exfoliated bentonite (EB) as the support. The morphology, crystal structure, optical absorption properties, specific surface area, and photochemical properties of the composite were characterized by XRD, TEM, XPS, UV-Vis DRS, BET, EIS, and photocurrent spectra. It was found that, LaFeO3 and Ag3PO4 formed a compact n-p heterojunction and uniformly dispersed on the surface of EB, which significantly broadened the light response range of Ag3PO4 and effectively promoted the separation of photogenerated electron-hole pairs. The photocatalytic performance of the samples were evaluated by photodegradation of phenol under visible light. The results showed, the degradation rate constant of Ag3PO4-LaFeO3/EB-40% was 4.2 times than that of bare Ag3PO4, which could achieve a 97% removal rate of phenol under neutral condition and 81.62% removal rate after recycling 4 times.