Graphene oxide surface chemistry regulated growth of SnO2 nanoparticles for electrochemical application

Wide applications of graphene oxide (GO) owe to unique abilities of its surface chemistry linked to the ubiquitous influence of oxygenated functional groups, especially for the electrochemical performance with metal oxides nanoparticles (NPs). In addition to the imbibed chemical property of NP, its size and shape are crucial for applications. In this context, the present work discusses the role of functional groups of GO in controlling the growth of SnO2 NPs and their electrochemical performances. SnO2, an important candidate for the hybrid capacitor, was grown by two different procedures to substantiate the role of functional groups of the GO. The in-situ process provided different shapes and sizes of SnO2 NPs in the GO matrix in contrast to the ex-situ procedure, which contained with quantum dot SnO2. X-ray diffraction, transmission electron microscopy, Raman studies revealed the structural details while Fourier transmission infrared spectroscopy and electron energy loss spectroscopy deciphered further information on the role of functional groups of GO for the growth of SnO2 NPs. The electrochemical study highlighted the importance of the functional groups and the size effect of NPs for their performance. The in-situ process with larger and irregular sizes of SnO2 NPs displayed a low electrochemical capacitance compared to the ex-situ process. •The ramification of functional GO in the growth of SnO2 nanoparticles is described.•Composites with GO using SnO2 quantum dots (QDs) were made by the in-situ and ex-situ growth.•Clear observation of dissimilar growth of metal oxide in the in-situ process is highlighted.•The electrochemical study supports the critical size effect of metal oxide and functional groups in GO.