Cu2+–Mn2+-Co-doped CdO nanocrystallites: comprehensive research on phase, morphology and optoelectronic properties

Insights into the consequence of (Al-Zn) dual-doping on structural, morphological, and optoelectrical properties of CdO thin films

The present study explores the structural, morphological, optical, and electrical properties of spray pyrolyzed (Al-Zn) dual-doped CdO thin films. The un-doped and (Al-Zn) dual-doped CdO thin films have been deposited on glass substrate using spray pyrolysis route at 325 °C. The physical properties of the doped samples were analyzed as a function of Zn concentration (2-5 mol%) with constant Al (3 mol%) concentration. XRD analysis confirms the successful incorporation of (Al-Zn) dual-doping into CdO crystal as well as the polycrystalline nature was evident. No phase transitions were apparent from XRD data while revealing the single cubic structure of all the samples. The surface morphology of the samples studied by SEM. It shows the formation of rock-shaped microstructure and the variation of grain size with doping concentrations. Optical analysis was done using UV-vis spectroscopy within the range of 300-1200 nm. Maximum value of transmittance was attained for 3% (Zn-Al)-doped CdO sample. The dual doping exhibits the broadening of band gap values (2.61-3.84 eV) whereas a decrease in extinction coefficient was noticed as a function of Zn doping concentration. Electrical analysis was done using the four-probe method and a high resistivity was seen for higher Zn concentration. Obtained results and precise comparison with some similar films suggested that 2% Zn and 3% Al co-doping can be a suitable candidate for optoelectronic devices.

Efficient Mesoporous MgO/g-C3N4 for Heavy Metal Uptake: Modeling Process and Adsorption Mechanism

Removing toxic metal ions arising from contaminated wastewaters caused by industrial effluents with a cost-effective method tackles a serious concern worldwide. The adsorption process onto metal oxide and carbon-based materials offers one of the most efficient technologies adopted for metal ion removal. In this study, mesoporous MgO/g-C₃N₄ sorbent is fabricated by ultrasonication method for the uptake Pb (II) and Cd (II) heavy metal ions from an aqueous solution. The optimum conditions for maximum uptake: initial concentration of metal ions 250 mg g^-1, pH = 5 and pH = 3 for Pb⁺⁺ and Cd⁺⁺, and a 60 mg dose of adsorbent. In less than 50 min, the equilibrium is reached with a good adsorption capacity of 114 and 90 mg g^-1 corresponding to Pb⁺⁺ and Cd⁺⁺, respectively. Moreover, the adsorption isotherm models fit well with the Langmuir isotherm, while the kinetics model fitting study manifest a perfect fit with the pseudo-second order. The as fabricated mesoporous MgO/g-C₃N₄ sorbent exhibit excellent Pb⁺⁺ and Cd⁺⁺ ions uptake and can be utilized as a potential adsorbent in wastewater purification.