Luan Jingfei, Shen Yue, Li Yanyan, Paz Yaron
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, China.
Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Materials (Basel). 2016 Sep 27;9(10):801. doi: 10.3390/ma9100801.
In order to develop original and efficient visible light response photocatalysts for degrading organic pollutants in wastewater, new photocatalysts Bi₂GaSbO₇ and Bi₂InSbO₇ were firstly synthesized by a solid-state reaction method and their chemical, physical and structural properties were characterized. Bi₂GaSbO₇ and Bi₂InSbO₇ were crystallized with a pyrochlore-type structure and the lattice parameter of Bi₂GaSbO₇ or Bi₂InSbO₇ was 10.356497 Å or 10.666031 Å. The band gap of Bi₂GaSbO₇ or Bi₂InSbO₇ was estimated to be 2.59 eV or 2.54 eV. Compared with nitrogen doped TiO₂, Bi₂GaSbO₇ and Bi₂InSbO₇, both showed excellent photocatalytic activities for degrading methylene blue during visible light irradiation due to their narrower band gaps and higher crystallization perfection. Bi₂GaSbO₇ showed higher catalytic activity compared with Bi₂InSbO₇. The photocatalytic degradation of methylene blue followed by the first-order reaction kinetics and the first-order rate constant was 0.01470 min, 0.00967 min or 0.00259 min with Bi₂GaSbO₇, Bi₂InSbO₇ or nitrogen doped TiO₂ as a catalyst. The evolution of CO₂ and the removal of total organic carbon were successfully measured and these results indicated continuous mineralization of methylene blue during the photocatalytic process. The possible degradation scheme and pathway of methylene blue was also analyzed. Bi₂GaSbO₇ and Bi₂InSbO₇ photocatalysts both had great potential to purify textile industry wastewater.
为了开发用于降解废水中有机污染物的新型高效可见光响应光催化剂，首先采用固相反应法合成了新型光催化剂Bi₂GaSbO₇和Bi₂InSbO₇，并对其化学、物理和结构性质进行了表征。Bi₂GaSbO₇和Bi₂InSbO₇以焦绿石型结构结晶，Bi₂GaSbO₇或Bi₂InSbO₇的晶格参数分别为10.356497 Å或10.666031 Å。Bi₂GaSbO₇或Bi₂InSbO₇的带隙估计为2.59 eV或2.54 eV。与氮掺杂TiO₂相比，Bi₂GaSbO₇和Bi₂InSbO₇由于其较窄的带隙和较高的结晶完整性，在可见光照射下对亚甲基蓝的降解均表现出优异的光催化活性。与Bi₂InSbO₇相比，Bi₂GaSbO₇表现出更高的催化活性。以Bi₂GaSbO₇、Bi₂InSbO₇或氮掺杂TiO₂为催化剂时，亚甲基蓝的光催化降解遵循一级反应动力学，一级速率常数分别为0.01470 min⁻¹、0.00967 min⁻¹或0.00259 min⁻¹。成功测量了CO₂的释放和总有机碳的去除，这些结果表明在光催化过程中亚甲基蓝不断矿化。还分析了亚甲基蓝可能的降解方案和途径。Bi₂GaSbO₇和Bi₂InSbO₇光催化剂在净化纺织工业废水方面都具有巨大潜力。
