Hydrothermal Synthesis of Reduced Graphene Oxide/Silver Nanocomposite Without Addition of Reducing Agent

Visible Light-Driven Photoelectrocatalytic Water Splitting Using Z-Scheme Ag-Decorated MoS2/RGO/NiWO4 Heterostructure

“…However, the atomic percentage of these peaks in the GO sample (Figure S4a) was 36.1% (C–C), 55.8% (C–O), and 8.1% (CO), respectively. Thus, the XPS analysis indicates that the total oxygen content of 63.9% (C–O: 55.8% and CO: 8.1%) in GO was reduced to 20.5% (C–O: 16.6% and CO: 3.9%) in the Ag-MRGON sample, while the corresponding nonoxygenated sp 2 carbon content of 36.1% increased to 79.5%, imposing the successful reduction of GO in the Ag-MRGON during the hydrothermal process along with the reduction of Ag (I) to metallic Ag NPs . The Ni 2p high-resolution spectrum (Figure c) splits into two spin–orbit doublets at 856.3 (Ni 2p 3/2 ) and 873.8 eV (Ni 2p 1/2 ), along with their corresponding shake-up satellites (Sat.).…”

“…For the Ag-MRGON heterojunction, in comparison with the XRD pattern of the MoS 2 /NiWO 4 heterojunction, two weak diffraction peaks at 25.8 and 31.7°F It is also worth mentioning that GO was used as a promoter for the Ag (I) reduction to metallic Ag NPs through the hydrothermal treatment. 36 The appearance of a weak and broad diffraction peak for the RGO (002) plane at 25.8°with a decrease in the interlayer spacing to 0.34 nm and the disappearance of the intense diffraction peak of the GO (001) plane at 11.8°in the pattern of the Ag-MRGON heterojunction verify the reduction of GO to RGO (see Figure 1). Moreover, the weak and broad nature of the (002) peak indicates the poor ordering of the NSs along the stacking direction, imposing the formation of single or few layers of RGO NSs.…”

“…Indeed, as expected, the developed Z-scheme Ag-MRGON heterostructure exhibits highly enhanced PEC activity (see section 2.4). 40,41 The existence of constituent elements in the Z-scheme Ag-MRGON heterojunction was affirmed by energy-dispersive Xray spectrometry (EDX), as presented in 36 The Ni 2p high-resolution spectrum (Figure 3c) splits into two spin−orbit doublets at 856.3 (Ni 2p 3/2 ) and 873.8 eV (Ni 2p 1/2 ), along with their corresponding shake-up satellites (Sat.). The spin−orbit separation is 17.5 eV that is an agreement with the reported values for NiWO 4 NPs.…”

“…These two peaks are indexed to the (002) and (100) crystal planes of RGO and Ag NPs, respectively, which demonstrate the existence of RGO and Ag NPs in this sample. It is also worth mentioning that GO was used as a promoter for the Ag (I) reduction to metallic Ag NPs through the hydrothermal treatment . The appearance of a weak and broad diffraction peak for the RGO (002) plane at 25.8° with a decrease in the interlayer spacing to 0.34 nm and the disappearance of the intense diffraction peak of the GO (001) plane at 11.8° in the pattern of the Ag-MRGON heterojunction verify the reduction of GO to RGO (see Figure ).…”