Mano Ganapathy, Harinee Subramanian, Sridhar Sampath, Ashok Mahalingam, Viswanathan Alagan
Department of Physics, University College of Engineering Bharathidasan Institute of Technology (BIT-Campus), Anna University, Tiruchirappalli, 620024, Tamil Nadu, India.
Department of Environmental Engineering, National Ilan University, Yilan, Taiwan.
Sci Rep. 2020 Feb 10;10(1):2224. doi: 10.1038/s41598-020-59066-4.
ZnO, PbS and ZnO-PbS heterojunction were prepared by microwave irradiation to improve the organic pollutants degradation under visible light irradiation. Hexagonal (wurtzite) and cubic crystal structure of ZnO and PbS respectively were confirmed by PXRD. Nano-plate, nano-sponge and nano-sponge imprinted over nano-sheet like morphology of ZnO, PbS and ZnO-PbS respectively were revealed through FESEM analysis. HR-TEM analysis provides the formation of heterojunction. XPS analysis shows the presence of the ZnO-PbS heterojunction. UV-Visible spectroscopy confirms the enhanced visible light response of ZnO-PbS heterojunction than the bare ZnO. The PL and EIS results indicate ZnO-PbS heterojunction exhibited lowest recombination of excitons and electron transfer resistance. Synergistic effect of ZnO-PbS heterojunction leads to efficient degradation against organic pollutants than bare ZnO and PbS. Aniline and formaldehyde were successfully degraded around 95% and 79% respectively, under solar light irradiation. As-prepared photocatalysts obeys pseudo first order reaction kinetics. HPLC analysis also confirms the successful mineralization of organic pollutants into water and CO.
通过微波辐射制备了氧化锌（ZnO）、硫化铅（PbS）和氧化锌-硫化铅（ZnO-PbS）异质结，以提高可见光照射下有机污染物的降解效果。通过粉末X射线衍射（PXRD）分别证实了ZnO和PbS的六方（纤锌矿）和立方晶体结构。通过场发射扫描电子显微镜（FESEM）分析分别揭示了ZnO、PbS和ZnO-PbS呈现出纳米片状、纳米海绵状以及纳米海绵在纳米片状上的印记状形态。高分辨透射电子显微镜（HR-TEM）分析证实了异质结的形成。X射线光电子能谱（XPS）分析表明存在ZnO-PbS异质结。紫外-可见光谱证实了ZnO-PbS异质结比纯ZnO具有更强的可见光响应。光致发光（PL）和电化学阻抗谱（EIS）结果表明ZnO-PbS异质结表现出最低的激子复合和电子转移电阻。ZnO-PbS异质结的协同效应导致其对有机污染物的降解效率比纯ZnO和PbS更高。在太阳光照射下，苯胺和甲醛分别成功降解了约95%和79%。所制备的光催化剂符合准一级反应动力学。高效液相色谱（HPLC）分析也证实了有机污染物成功矿化为水和二氧化碳。
