Influence of Ni substitution on opto-magnetic and electrochemical properties of CTAB-capped mesoporous SnO 2 nanoparticles

Nickel-doped mesoporous tin dioxide Sn1−xNixO2 (where x = 0, 0.01, 0.03, and 0.05) nanoparticles using cetyltrimethylammonium bromide (CTAB) as surfactant were prepared by hydrothermal technique. The morphology, structure, optical, magnetic, and electrochemical properties of the mesoporous tin oxide nanopowders were investigated extensively as a function of nickel doping concentration. XRD patterns confirm that the obtained nanoparticles are SnO2 with tetragonal rutile structure fully compatible with JCPDS card no. 41-1445. The crystallite size was measured by Scherrer formula and was found to be 39–30 nm. FTIR findings showed that the change in the shapes and positions of absorption peaks shows the existence of stretching modes that give an implication of successful doping Ni to tin dioxide nanopowders. To analyze the optical properties, the wavelength range 350–1100 nm was used. The result demonstrates that the existence of specifically permitted optical transitions with energy gap varies in the range of 3.6–2.3 eV with Ni concentration. The electrochemical analysis using cyclic voltammetry showed a pair of redox peaks in Ni-doped tin dioxide electrode. The electrochemical impedance spectroscopy (EIS) denoted a significant decrease in charge transfer resistance (RCT), indicating an improved electrochemical performance of the electrode. Ni doping was found to be interesting due to the co-existence of room-temperature ferromagnetism and an enhanced electrochemical behavior, hence making it a probable material for magnetically controlled electrochemical cells.