硅酸铁钠光催化剂的表面调控及光还原除Cr(Ⅵ)性能研究
Study on surface regulation of sodium ferric silicate photocatalyst and its enhanced Cr(Ⅵ)photoreduction properties
严钰 1周文元 1杨韵斐 1吴俊书 1王金淑 1孙领民1
作者信息
摘要
绿色、价廉、稳定的硅酸盐类光催化剂是当前研究热点之一.硅酸铁钠(NaFeSi2O6,SFS)是一种链式硅酸盐,组成元素简单,能够吸收可见光,因而受到人们的关注.首先通过水热方法合成原始SFS粉末,而后经热还原过程调控SFS表面的微结构与Fe(Ⅲ)/Fe(Ⅱ)比率,制备出最优的改性SFS用于Cr(Ⅵ)还原.研究发现,经过200℃热还原之后的SFS-200,比表面积增大了43%、孔体积增大到0.081 cm3/g、Fe(Ⅱ)占比从33%提高到45%,显著提高了其对Cr(Ⅵ)的催化还原活性.同时,探究了SFS-200催化剂用量、还原时间、草酸助剂用量、Cr(Ⅵ)浓度等因素对催化性能的影响.分析发现,催化体系中Fe(Ⅱ)-C2O4·-是主要活性物质,维持Fe(Ⅲ)-Fe(Ⅱ)的化学循环以增强SFS-200的Cr(Ⅵ)高效光还原去除能力.该研究提供了一条制备高性能硅酸铁钠光催化剂用于Cr(Ⅵ)污水净化的有效途径,具有较大的应用潜力.
Abstract
Silicate-based catalysts have become the focus of current research because of their green,low-cost and stable characteristics.Sodium ferric silicate(NaFeSi2O6,SFS)is a chain silicate with simple composition and ability to absorb vis-ible light,which has attracted people's attention.Firstly,the original SFS powder was synthesized by hydrothermal method,and then the microstructure and Fe(Ⅲ)/Fe(Ⅱ)ratio of the SFS surface were regulated by thermal reduction process to pre-pare the optimal modified SFS for Cr(Ⅵ)reduction.It was found that after thermal reduction at 200℃,the specific surface area of SFS-200 was increased by 43%,the pore volume was increased to 0.081 cm3/g,and the proportion of Fe(Ⅱ)was in-creased from 33%to 45%,significantly improving its catalytic reduction activity towards Cr(Ⅵ).Meanwhile,the effects of SFS-200 catalyst dosage,reduction time,oxalic acid promoter dosage,Cr(Ⅵ)concentration,and other factors on catalytic performance were investigated.It was found that Fe(Ⅱ)-C2O4·-was the main active substance in the catalytic system,main-taining the chemical cycle of Fe(Ⅲ)-Fe(Ⅱ)to enhance the efficient photo reduction removal ability of Cr(Ⅵ)by SFS-200.This study provided an effective way to prepare high-performance sodium ferric silicate photocatalyst for Cr(Ⅵ)waste-water purification,which had great potential for application.
关键词
硅酸铁钠/光催化/Cr(Ⅵ)Key words
sodium ferric silicate/photocatalysis/Cr(Ⅵ)引用本文复制引用
出版年
2024
NETL
NSTL
万方数据