Strategic Ni integration to study its impact on the photoluminescence and photocatalytic performances of SnO2 nanorod architecture

Abstract

The sol-gel process was utilized to fabricate SnO₂ nanoparticles, both in their pure form and with the addition of Ni dopants. The nanoparticles obtained were further examined to ascertain the characteristics associated with their structure, alterations in band gap, and photocatalytic performance. The insertion of nickel ions into tin sites hinders the formation of grain growth in tin oxide. The variation in the valence states and ionic radius of Sn⁴⁺ and Ni²⁺ ions, as revealed by X-ray diffraction (XRD) study, accounts for this disparity. FTIR measurements indicate the existence of stretching vibrations of metal-oxygen bonds that include Ni ions in the doped samples. The photoluminescence (PL) analysis reveals that the introduction of nickel doping alters the band structure of SnO₂, leading to the creation of additional defect states, such as oxygen vacancies inside the crystal lattice. A study was undertaken to investigate the photocatalytic (PC) activity of SnO₂ in the presence of Ni dopants. The results revealed a noticeable improvement in the efficiency of photodegradation. The degradation of Congo red (CR) dye using Ni–SnO₂ nanocrystals achieves an efficiency of 94.88 % within a duration of 180 ​min. An analysis has been conducted on the impact of dye content, photocatalyst dosage, and pH on the degradation efficiency. As per the study, lower dose of Ni–SnO₂ has shown better degradation efficiency in comparison to other studies. The improved performance of Ni–SnO₂ can be ascribed to two main factors: the inhibition of carrier recombination due to the inclusion of defective states, and the production of hydroxyl radicals (OH•). The stability and reusability of these photocatalysts have been noted in their efficient application for environmental remediation.