Nadeem Muhammad Shahid, Munawar Tauseef, Mukhtar Faisal, Batool Sana, Hasan Murtaza, Akbar Usman Ali, Hakeem Abbas Saeed, Iqbal Faisal
Institute of Physics, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan.
Institute of Bio-Chemistry, Bio-Technology, and Bioinformatics, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan.
Environ Sci Pollut Res Int. 2022 Jul;29(33):50317-50334. doi: 10.1007/s11356-022-19271-2. Epub 2022 Feb 28.
Energy-levels well-matched direct Z-scheme ZnNiNdO/CdS heterojunction was successfully fabricated using facile co-precipitation and ultra-sonication techniques and characterized with XRD, FTIR, Raman, PL, UV-vis, and FE-SEM. The XRD diffractograms confirmed the co-doping of Ni-Nd in ZnO and the formation of heterostructured nanocomposite. FTIR and Raman data showed the presence of metal-oxygen vibration and optical phonon modes of ZnO and CdS. FE-SEM images exhibited the network type morphology. The energy bandgap was redshifted by co-doping (3.37-2.9 eV) and was further reduced (2.6 eV) by making a composite with CdS. The ZnNiNdO/CdS catalyst degraded 99.7, 49, 96.6, 98.6, and 98.6% methylene blue (MB), p-nitroaniline (P-Nitro), methyl orange (MO), methyl red (MR), and rhodamine B (RhB) dyes under 50 min sunlight irradiation. Moreover, ZnNiNdO/CdS showed intense inhibition activity towards Staphylococcus aureus, Escherichia coli, Proteus vulgaris, and Pseudomonas aeruginosa bacterial strains with maximum inhibition zone diameters 30, 33, 27, and 31 mm, respectively. The synergistic effects arising from band alignment can lead to efficient vectorial charge separation, transportation, and lower recombination of photoinduced charge carriers, ultimately boosting photocatalytic and antibacterial performance. The ZnNiNdO/CdS photocatalyst has higher stability up to the 7th cycle towards MB dye with ~ 5% deficit in degradation efficiency. The higher generation of superoxide and hydroxyl radical was confirmed by species trapping experiments responsible for photodegradation of dyes molecules. Furthermore, the results showed that the photocatalytic and antibacterial performance of pristine ZnO can be enhanced by co-doping and tuning energy bandgap.
采用简便的共沉淀和超声技术成功制备了能级匹配良好的直接Z型ZnNiNdO/CdS异质结，并用XRD、FTIR、拉曼、PL、紫外可见光谱和场发射扫描电子显微镜对其进行了表征。XRD衍射图谱证实了Ni-Nd在ZnO中的共掺杂以及异质结构纳米复合材料的形成。FTIR和拉曼数据表明存在ZnO和CdS的金属-氧振动和光学声子模式。场发射扫描电子显微镜图像呈现出网络型形态。通过共掺杂使能带隙发生红移（从3.37 eV降至2.9 eV），与CdS复合后能带隙进一步降低（至2.6 eV）。ZnNiNdO/CdS催化剂在50分钟阳光照射下对亚甲基蓝（MB）、对硝基苯胺（P-Nitro）、甲基橙（MO）、甲基红（MR）和罗丹明B（RhB）染料的降解率分别为99.7%、49%、96.6%、98.6%和98.6%。此外，ZnNiNdO/CdS对金黄色葡萄球菌、大肠杆菌、普通变形杆菌和铜绿假单胞菌菌株表现出强烈的抑制活性，最大抑菌圈直径分别为30、33、27和31毫米。能带排列产生的协同效应可导致光生电荷载流子的有效矢量电荷分离、传输以及较低的复合率，最终提高光催化和抗菌性能。ZnNiNdO/CdS光催化剂在第7个循环对MB染料具有较高的稳定性，降解效率仅有约5%的下降。通过捕获实验证实，超氧自由基和羟基自由基的大量生成是染料分子光降解的原因。此外，结果表明，通过共掺杂和调节能带隙可以提高原始ZnO的光催化和抗菌性能。
