Abstract
We explore the effect of Mo doping over the large enhancement of electrochemical property of Mo doped SnO2 quantum dots (3-5 nm) grown over rGO (reduced graphene oxide) sheets by a soft chemical process in ambient conditions. The composites were prepared over a range of Mo doping concentrations (0-10%) and 5 % Mo doping had achieved the best energy storage characteristics. The capacity of the active material could reach ~851 mAh g-1 (@ 78mAg−1) in the beginning and that retained ~89 % (~758 mAh g-1) with superior cyclic stability (100 cycles) and rate capability (506 mAh g-1 @ ~1.5 A g-1). Addition of the reductant of 0.06 mol during the synthesis procedure led to further improvement of the capacity to ~875 mAh g−1 (~92 % retention) and the rate capability (~587 mAh g−1). These impressive results are ascribed to the distribution of Mo doped SnO2 QDs, doping of Mo6+ at Sn4+ lattice sites providing more electrons for easy electrical transport, reduction of GO (graphene oxide) to rGO. Mo doping led to the decline in the charge transfer resistance (Rct) from 14.99 Ω for un-doped SnO2/rGO to 14.09 Ω (2.5 %), 11.61 Ω (5 %) and 11.4 Ω (10 %) and promote the electrochemical property of the composite. A simple room temperature synthesis process was used to produce Mo doped SnO2/rGO nanocomposite and that can be employed for the production of many other oxides and their composites for interesting applications.
