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A facile and rapid method to synthesize graphene/layered double hydroxide (LDH) nanohybrids by a microwave technique is demonstrated. The synthesis procedure involves hydrothermal crystallization of Zn–Al LDH at the same time in situ reduction of graphene oxide (GO) to graphene. The microstructure, composition, and morphology of the resulting graphene/LDH nanohybrids were characterized. The results confirmed the formation of nanohybrids and the reduction of graphene oxide. The growth mechanism of LDH and in situ reduction of GO were discussed. The LDH sheet growth was found to prevent the scrolling of graphene layers in resulting hybrids. The electrochemical properties exhibit superior performance for graphene/Zn–Al LDH hybrids over pristine graphene. The present approach may open a strategy in hybridizing graphene with multimetallic nano-oxides and hydroxides using microwave method.

Recently, the development of layered two-dimensional (2D) material-based nanostructured hybrids has witnessed a remarkable advancement as energy storage and conversion materials. Herein, we present an all-solid-state and scalable approach to integrate 2D−2D-type SnS 2 and graphene-layered nanosheets (SnS 2 /G) and assessed its potential as an active material for the high-performance supercapacitor and electrocatalyst for the hydrogen evolution reaction (HER). In this in situ solvent-free strategy, a tin precursor and graphite oxide (GO) were homogeneously ball-milled with surfeit yet nontoxic elemental sulfur and subjected to a moderate thermal treatment to obtain a unique 2D−2D-type SnS 2 /G nanohybrid. The characterization revealed that the in situ formed SnS 2 nanosheets were uniformly distributed and wrapped within graphene layers. The resulting nanohybrids demonstrated a superior specific capacitance of 565 F g −1 and retain a significant charge−discharge cyclic stability (90%/3000 cycles). Similarly, a resultant symmetric device delivered a high energy density of 23.5 Wh kg −1 and power density 880 W kg −1 at a current density of 1 A g −1 . Furthermore, the resulting SnS 2 / G nanohybrid provided a much lower HER overpotential of 0.36 V than SnS 2 (0.6 V) to attain a current density of 10 mA cm −2 in the alkaline electrolyte. The proposed strategy presents an environmentally benign avenue to integrate electrochemically active metal-sulfide-based 2D−2D-type nanostructured materials with superior energy storage and conversion capabilities.

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A facile and eco-friendly strategy is described for the synthesis of ZnS-ZnO/graphene heterostructured nano-photocatalysts for the first time. This solvent-free and technologically scalable method involves solid-state mixing of graphite oxide (GO), Zn salt and surfeit yet non-toxic elemental sulfur using ball-milling followed by thermal annealing. The as-formed hybrids are composed of uniformly distributed in-situ formed ZnS-ZnO nanoparticles simultaneously within the thermally reduced GO (graphene) matrix. A series of hybrid compositions with varying content of ZnS/ZnO and graphene were prepared and thoroughly characterized. Further, the effect of heterostructure composition on the photocatalytic properties was investigated under visible-light illumination. The synergistic ZnS-ZnO/graphene hybridization promoted the band-gap narrowing compared to the pristine ZnS nanoparticles. The ZnS:ZnO composition was controlled by graphite oxide under thermal treatment and observed to be a crucial factor in enhancement of photocatalytic activity. As a proof of concept, the phase optimized and surface enhanced ZnS-ZnO/graphene nano-photocatalysts was tested towards visible light driven photocatalytic degradation of environmentally harmful organic dyes and toxic phenol molecules from aqueous media. The presented cost-effective strategy provides high potential in large-scale production of heterostructured nano-photocatalysts for environmental remediation and photocatalytic greener production of hydrogen.