Sonochemical synthesized BaMoO4/ZnO nanocomposites as electrode materials: A comparative study on GO and GQD employed in hydrogen storage

Due to poor rate proficiency and electrochemical capacity of transition metal oxides, production electrode materials as operative way to develop the electrochemical performance is a crucial strategy to make sure the great electroactive sites and fast electron/ion diffusion route. In order to solve this problem, carbon-based nanocomposites as conductive substrates are applied. The nanostructured BaMoO₄/ZnO was produced by sonochemical method in the presence of tween 20 as stabilizing agent. Effect of graphene quantum dots (GQDs) and graphene oxide (GO) for developing hydrogen capacity of BaMoO₄/ZnO was studied by providing representative composites of BaMoO₄/ZnO-GQDs and BaMoO₄/ZnO-GO. For this purpose, GQDs was synthesized using green source of Spiraea crenata and the GO provided by commercial company. The structural analysis shows preparation of scales-like morphology of BaMoO₄/ZnO without any impurities through SEM, TEM, XRD, EDS and FT-IR characterization data. Also, the specific surface area for BaMoO₄/ZnO-GQDs (11 m²/g) and BaMoO₄/ZnO-GO (124 m²/g) nanocomposites increased by comparing to BaMoO₄/ZnO (9.1 m²/g). The resultant nanocomposites used as new active compounds for applying in hydrogen storage strategies using cyclic voltammetry and chronopotentiometry tests. Comprehensively, the hydrogen capacitance after 15 cycles was demonstrated on the nanostructured BaMoO₄/ZnO about 129 mAhg⁻¹. It demanded the maximum capacitance for BaMoO₄/ZnO-GQDs and BaMoO₄/ZnO-GO nanocomposites were 284 and 213 mAhg⁻¹ respectively, which was higher than the initial nanostructured BaMoO₄/ZnO. It was exposed from the carbon based structured that; the endorsed electrochemical hydrogen storage (EHS) performance is ascribed to the reaction of the redox pair of Mo⁶⁺ /Mo⁵⁺ at the active sites throughout the EHS procedure. This study delivers a novel plan and potential sorption electrode materials to progress the intrinsic action of conductive compounds.