Review on the improvement of the photocatalytic and antibacterial activities of ZnO

The emergence of quantum dot-sensitized solar cells (QDSSCs) has provided an alternative way to harvest sunlight for energy conversion. Among all the QDSSCs, cadmium chalcogenide (CdX, X=S, Se or Te) based QDSSCs have gained a significant interest due to their easy fabrication, low cost and high performance. However, their performance still does not match with that of their dye-sensitized solar cells (DSSCs) counterpart. In this review, the concept and mechanism behind the QDSSCs are reviewed. Fabrication methods and possible approaches for improving the Cd chalcogenide QDSSC performance are also discussed. It is worthwhile to note that the efficiency of a QDSSC depends on the fabrication method of the quantum dots, morphology of the photoanode, type of electrolyte used and the choice of the counter electrode. It is therefore, imperative for engineering of materials and optimization of the fabrication method for the improvement of QDSSCs performance.

Quantum dot-sensitized solar cells—perspective and recent developments: A review of Cd chalcogenide quantum dots as sensitizers

Antibacterial metals and alloys for potential biomedical implants.

A review on bidirectional analogies between the photocatalysis and antibacterial properties of ZnO

In this research, a facile co-precipitation method was used to synthesize pure and Mg-doped ZnO nanoparticles (NPs). The structure, morphology, chemical composition, and optical and antibacterial activity of the synthesized nanoparticles (NPs) were studied with respect to pure and Mg-doped ZnO concentrations (0–7.5 molar (M) %). X-ray diffraction pattern confirmed the presence of crystalline, hexagonal wurtzite phase of ZnO. Scanning electron microscope (SEM) images revealed that pure and Mg-doped ZnO NPs were in the nanoscale regime with hexagonal crystalline morphology around 30–110 nm. Optical characterization of the sample revealed that the band gap energy (Eg) decreased from 3.36 to 3.04 eV with an increase in Mg2+ doping concentration. Optical absorption spectrum of ZnO redshifted as the Mg concentration varied from 2.5 to 7.5 M. Photoluminescence (PL) spectra showed UV emission peak around 400 nm. Enhanced visible emission between 430 and 600 nm with Mg2+ doping indicated the defect density in ZnO by occupying Zn2+ vacancies with Mg2+ ions. Photocatalytic studies revealed that 7.5% Mg-doped ZnO NPs exhibited maximum degradation (78%) for Rhodamine B (RhB) dye under UV-Vis irradiation. Antibacterial studies were conducted using Gram-positive and Gram-negative bacteria. The results demonstrated that doping with Mg ions inside the ZnO matrix had enhanced the antibacterial activity against all types of bacteria and its performance was improved with successive increment in Mg ion concentration inside ZnO NPs.

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Influence of Mg Doping on ZnO Nanoparticles for Enhanced Photocatalytic Evaluation and Antibacterial Analysis

Tuning the combined magnetic and antibacterial properties of ZnO nanopowders through Mn doping for biomedical applications

Influence of Sn doping level on antibacterial activity and certain physical properties of ZnO films deposited using a simplified spray pyrolysis technique

CdS films were fabricated using Successive Ionic Layer Adsorption and Reaction (SILAR) technique from starting solutions having S:Cd ratio 1:1, 3:1, 5:1 and 7:1 and their structural, surface morphological and optical properties were investigated and compared with that of their chemical bath deposited counterparts. The X-ray diffraction profiles showed that the films have cubic crystal structure with preferential orientation along the (111) plane and the intensity of the (111) plane increases for both the techniques as the S:Cd ratio increases. The energy dispersive X-ray analysis revealed that for SILAR deposited films, the S/Cd ratio in the sample increases from 0.8308 (for S:Cd 1:1) to 1.04 (for S:Cd 7:1) as the molar concentration of sulphur in the starting solution increases. But for CBD films, the S/Cd is only ~0.80 for all concentrations of sulphur in the starting solution. The optical band gap increases with the increase in S:Cd ratio in the starting solution in both the techniques.

Photovoltaic properties of nanocrystalline CdS films deposited by SILAR and CBD techniques—a comparative study

Effect of source material on the transparent conducting properties of sprayed ZnO:Al thin films for solar cell applications

Undoped and Doubly (Magnesium + Fluorine) doped zinc oxide (ZnO:Mg:F) thin films with different Mg doping levels (4, 8, 12 and 16 at.%) and constant F doping level (20 at.%) were fabricated by employing a simplified spray pyrolysis technique. The antibacterial and certain physical properties of the films were studied as a function of Mg doping level. All the films exhibited hexagonal wurtzite structure with preferential orientation along the (002) plane. A lesser electrical resistivity was achieved in the present study than earlier reports of ZnO:Mg films thanks to the simultaneous doping of F with Mg in ZnO films. From the optical studies, it was observed that, all the films showed good transparency (≈85 %) with significant enhancement in the optical band gap with Mg doping level. The obtained PL spectra were well corroborated with the structural and optical studies. Further, it was also found that the antibacterial activity of doubly doped ZnO films was enhanced remarkably by the increasing incorporation of Mg concentration.

N. Jabena Begum

Papers

Tuning the combined magnetic and antibacterial properties of ZnO nanopowders through Mn doping for biomedical applications

Influence of Sn doping level on antibacterial activity and certain physical properties of ZnO films deposited using a simplified spray pyrolysis technique

Photovoltaic properties of nanocrystalline CdS films deposited by SILAR and CBD techniques—a comparative study

Effect of source material on the transparent conducting properties of sprayed ZnO:Al thin films for solar cell applications

Enhancement in the electrical and antibacterial properties of sprayed ZnO films by simultaneous doping of Mg and F