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

Acoustotemplating: rapid synthesis of freestanding quasi-2D MOF/graphene oxide heterostructures for supercapacitor applications

“…24,75 While this means complete reduction of GO has not occurred, the shi in the (002) GO peak, nevertheless, affirms that partial reduction of GO has transpired. 76,77 We shall assert below that such partial, instead of complete, reduction of GO is actually advantageous in the current context-allowing some functional groups associated with the GO to be retained to facilitate attachment of the MOF, all the while generating an adequate amount of rGO to render the material sufficiently conductive.…”

“…87 Given the partial reduction that occurs, we expect the q-2D-MOF/rGO composite to comprise both GO and rGO domains, which is advantageous since the functionalized (GO) regions facilitate attachment of the q-2D-MOF whereas the graphitic (rGO) regions form conjugated p-p bonds across the aromatic rings in the GO/rGO/ MOF layers. 77 The latter, i.e., the p-p bonding, is pivotal to planar growth of the coordinated q-2D-MOF/GO composite, 88,89 in addition to enhancing its electrochemical properties by decreasing contact resistance and increasing electron transfer efficiency; 90,91 the sheet resistance of the samples was observed to decrease by ten-fold to 1.8 Â 10 8 U sq À1 following reduction from q-2D-MOF/GO to q-2D-MOF/rGO, consistent with MOF/GO composites with low GO content. 92 Finally, XPS analysis reveals three expected peaks in the wide-scan spectra of the q-2D-MOF/rGO composite (Fig.…”

Eco-Friendly Reduced Graphene Oxide Nanofilter Preparation and Application for Iron Removal

“…The UV-Vis absorbance of graphene oxide and reduced graphene oxide nanomaterials occurred at 230 and 281 nm, respectively (Figure 4), thus confirming the formation of reduced graphene oxide nanomaterial [12].…”

One Pot Microwave Irradiation Synthesis of Spherical and Nanotube Titanates Incorporated Reduced Graphene for Efficient Hydrogen Production Photo-Electrocatalytically

“…Constructively, our cost effective photocatalyst 50TNT-50GO has shown superior photoelectrocatalytic water splitting performances (9.2 mA cm -2 ) compared to others in literatures such as various black titania either produced via reduction by CaH 2 (1.99 mA cm -2 ) or Mg metal (3.1 mA cm -2 ) [19][20]. It also exceeds those of the ternary structured Ag/TiO 2 /CNT (0.9 mA cm -2 ), TiO 2 @RG (6.0 mA cm -2 ), reduced graphenegraphene oxide nanohybrid (61.35 μA/cm 2 ) and controlled lm of TiO 2 nanotubes (175 µA cm −2 ) [21][22][23][24] all performed in the same electrolyte.…”