Reduced graphene oxide-intercalated graphene oxide nano-hybrid for enhanced photoelectrochemical water reduction

Abstract This paper reports on the synthesis of reduced graphene oxide (RGO)-intercataled graphene oxide (GO) nano-hybrid and investigates its application in photoelectrochemical (PEC) water reduction. The optical, structural, and morphological properties of RGO-intercalated GO (RGO/GO) nano-hybrid were studied using UV–Visible spectroscopy, X-ray diffraction, and scanning electron microscopy, respectively. The reduction of GO to RGO was studied using FTIR spectroscopy. The XRD and FTIR investigation shows the strong π–π stacking interactions between the layered GO host–RGO guest sheets. An improvement in PEC water reduction activity was exhibited by RGO/GO nano-hybrid photoelectrode, with a maximum photocurrent of − 61.35 μA/cm 2 for RGO 1 wt% in GO versus − 42.80 μA/cm 2 for pristine GO photoelectrode (43% improvement). The mechanism for photocurrent enhancement was studied by electrochemical impedance analysis. The PEC performance enhancement of RGO/RO nano-hybrid photoelectrode is attributed to the strong π–π stacking interactions between RGO and GO, leading to superior electron collection and transportation by RGO and hence reduced charge carrier recombination. In addition, the UV–Visible absorption and Taut plot analysis showed the higher light harvesting efficiency of the RGO/GO compared to GO, displaying a band gap of 2.58 eV and 3.11 eV for RGO/GO and GO, respectively. The findings of this work show the potential of a strongly coupled layered host–guest nano-hybrids for high-performance optoelectronic materials. Graphic abstract