Synergetic Hybridization Effect of Homogeneously Mixed Inorganic and Graphene Nanosheets on the Photocatalytic Activity of Semiconductor

Abstract

Using the homogeneous colloidal mixture of conductive metal oxide nanosheet (NS) and reduced graphene oxide (rGO) NS as hybridization matrices provides universal way of optimizing the photocatalyst functionality of semiconductor nanocrystals. A self‐assembly between CdS quantum dots (QDs) and RuO2/rGO NSs yields strongly coupled ternary nanohybrids with enhanced photocatalytic activity and increased porosity. Even with its lower RuO2 content, the ternary CdS−RuO2/rGO nanohybrid exhibits notably higher photocatalytic activities for visible‐light‐induced H2 evolution and photocurrent generation than binary CdS−RuO2/rGO homologues, underscoring the synergetic hybridization effect of flexible rGO and hydrophilic RuO2 NSs. In comparison with single RuO2/rGO NSs, their homogeneous mixture can play better roles of photosensitizers and cocatalysts, which is mainly responsible for remarkable improvement of photocatalytic activity upon the cohybridization with mixed RuO2/rGO NSs. The current study underscores that cohybridization with complementary inorganic and graphene NSs can provide an efficient and economically feasible methodology to explore novel high‐performance catalyst materials.

Multilayer Conductive Hybrid Nanosheets as Versatile Hybridization Matrices for Optimizing the Defect Structure, Structural Ordering, and Energy‐Functionality of Nanostructured Materials

“…Actually, it has been well‐documented that the incorporation of rigid inorganic NS is effective in depressing the dense packing of graphene primary crystallites, resulting in the improvement of porosity. [ 15,23,24 ]…”

“…To determine the optimal composition, several MSGR nanohybrids were synthesized with various RuO 2 /MoS 2 ratios (0−10 wt%), since the content of conductive NS has been well-known to have significant influence on the electrocatalyst performance of nanohybrids. [12,15] In the compositional ranges employed, the MSGR nanohybrid with the RuO 2 /MoS 2 ratio of 7.5 wt% showed well-ordered hybrid structure and an optimized electrocatalyst performance (Figures S2,S3, Supporting Information). As presented in Figure S3a,b, Supporting Information, the increase of trilayer prGO/RuO 2 /prGO NS content resulted in a significant lowering of the overpotential at 10 mA cm −2 (i.e., 298 mV for MSGR0, 152 mV for MSGR3, 136 mV for MSGR5, and 97 mV for MSGR7.5 ) and the accompanying depression of Tafel slopes.…”

“…To probe the possible interference effect of chemical composition on the HER activity of the restacked nanohybrid, another reference for a binary MoS 2 −RuO 2 nanohybrid with the same molar ratio as MSGR was prepared by restacking a colloidal MoS 2 /RuO 2 NS mixture with a PDDA cation (denoted as the rMSR nanohybrid), since the change of RuO 2 NS content would cause notable change of electrocatalyst performance. [8,15] This system was examined due to the fact that the different charge densities of pRuO 2 and the prGO NSs force the MSR reference to have a different ratio of MoS 2 :conductive NSs from that of MSGR to ensure that the superlattice structure is maintained. As shown in Figure S11, Supporting Information, this rMSR nanohybrid displayed a poor HER activity compared to MSGR, with a higher overpotential of 184 mV being observed at −10 mA cm −2 .…”

“…As an example, multilayer multicomponent rGO/transition metal oxide (TMO)/rGO NSs are supposed to exhibit a high structural rigidity and surface bonding controllability originating from a robust interstratified 2D structure with a tunable composition. [ 15 ] Such physical features of multilayer hybrid NSs are advantageous for improving the structural ordering and charge transport properties of hybridized 2D nanospecies via the flattening of layered crystallites on a robust NS substrate. For example, an exfoliated 1T′‐MoS 2 NS, one of the most efficient electrocatalysts for hydrogen evolution reaction (HER), suffers from low structural stability caused by the facile defect formation/lateral fracture and the resulting degradation of electrocatalyst performance, [ 16 ] which might be relieved by the hybridization with robust multilayer NS substrate.…”

Adsorptive removal of Rhodamine B dye from aqueous solution by using graphene–based nickel nanocomposite

“…In another case, along with synthesis and characterization and preliminary degradation of RhB dye removal, they have verified the usage of composite for electrode material as super capacitors [ 13 ]. The graphene based nanocomposites are also used in devices like dye sensitized solar cell [ 14 ], enhanced X-ray photon response [ 15 ], enhanced performance of light-controlled conductive switching [ 16 ], and photocatalytic activity in semiconductor [ 17 ].…”