Jin Xin-Yan, Ying Wan-Ying, Che Rui-Jie, Xiao Ping, Zhou Yu-Qing, Liu Yan, Liu Meng-Yu, Chen Shuo-Ping
College of Materials Science and Engineering, Guilin University of Technology Guilin 541004 China
RSC Adv. 2022 Aug 19;12(36):23692-23703. doi: 10.1039/d2ra03709b. eCollection 2022 Aug 16.
To provide a low-cost photocatalyst and new methodology for the utilization of waste rice noodle (WRN), a carbon quantum dots/zinc oxide (CQDs/ZnO) composite using WRN as the raw material was synthesized and characterized. The CQDs/ZnO composite based on WRN exhibited a highly efficient photocatalytic degradation effect on various organic pollutants and could be a good alternative for commercial ZnO. For methylene blue, the CQDs/ZnO composite showed a good degradation rate of 99.58% within 40 min, a high degradation rate constant of 0.2630 min, and could be recycled and reused for ten photocatalytic cycles without an appreciable decrease in the degradation effect, which was much better than that of commercial ZnO. The resulting CQDs/ZnO composite also displayed a nice photocatalytic degradation effect on other common organic pollutants, such as malachite green, methyl violet, basic fuchsin, rhodamine B, aniline and tetracycline. In particular, it could achieve excellent photocatalytic degradation on malachite green with an extremely high degradation rate constant of 1.9260 min. Besides, the CQDs/ZnO composite could also be used to control the pollution of tetracycline or aniline. The introduction of CQDs based on WRN to ZnO resulted in efficient electron-hole pair separation and enabled more photogenerated electrons to reduce O and more photogenerated holes to oxidize HO, which caused stronger abilities in producing radicals (such as O˙ and ˙OH) and a better photocatalytic degradation effect to organic pollutants.
为了提供一种低成本的光催化剂以及利用废弃米粉（WRN）的新方法，合成并表征了一种以WRN为原料的碳量子点/氧化锌（CQDs/ZnO）复合材料。基于WRN的CQDs/ZnO复合材料对各种有机污染物表现出高效的光催化降解效果，并且可能成为商业氧化锌的良好替代品。对于亚甲基蓝，CQDs/ZnO复合材料在40分钟内显示出99.58%的良好降解率、0.2630 min的高降解速率常数，并且可以循环再利用十个光催化循环，降解效果没有明显下降，这比商业氧化锌要好得多。所得的CQDs/ZnO复合材料对其他常见有机污染物，如孔雀石绿、甲基紫、碱性品红、罗丹明B、苯胺和四环素，也表现出良好的光催化降解效果。特别是，它对孔雀石绿能实现优异的光催化降解，降解速率常数高达1.9260 min。此外，CQDs/ZnO复合材料还可用于控制四环素或苯胺的污染。基于WRN的CQDs引入到ZnO中导致了有效的电子-空穴对分离，使更多的光生电子还原O，更多的光生空穴氧化HO，从而产生更强的产生自由基（如O˙和˙OH）的能力以及对有机污染物更好的光催化降解效果。
