A Conductive Hybridization Matrix of RuO₂ Two‐Dimensional Nanosheets: A Hybrid‐Type Photocatalyst

Abstract

A universal methodology to efficiently improve the photocatalyst performance of semiconductors was developed by employing exfoliated RuO2 two-dimensional nanosheets as a conducting hybridization matrix. The hybridization with a RuO2 nanosheet is easily achieved by crystal growth or electrostatically derived anchoring of semiconductor nanocrystals on the RuO2 nanosheet. An enhanced chemical interaction of inorganic semiconductor with hydrophilic RuO2 nanosheet is fairly effective in optimizing their photocatalytic activity and photostability by the enhancement of charge separation and charge mobility. The RuO2 -containing nanohybrids show much better photocatalyst functionalities than do the graphene-containing ones. The present study clearly demonstrates that hydrophilic RuO2 nanosheets are superior hybridization matrices, over the widely used hydrophobic graphene nanosheets, for exploring new efficient hybrid-type photocatalysts.

Application of Exfoliated Inorganic Nanosheets for Strongly‐Coupled Hybrid Photocatalysts

“…Copyright 2011 American Chemical Society. b) Self‐assembly–phase transformation route, c) self‐assembly–crystal growth route, d) surface modification–self‐assembly route, and e) link‐mediated self‐assembly route …”

“…First, the Ag + cations are adsorbed on the surface of the exfoliated RuO 2 nanosheet. Then, the reaction between the adsorbed Ag + and phosphate ions induces the formation of Ag 3 PO 4 nanocrystals on the surface of the exfoliated RuO 2 nanosheet, yielding the RuO 2 –Ag 3 PO 4 nanohybrid …”

“…In combination with the above‐mentioned experimental techniques, density functional theory (DFT) calculation is quite useful in elucidating the atomic and electronic structures of inorganic nanosheets and their nanohybrids. Of prime importance is that the DFT technique can provide crucial information for understanding the interfacial chemical interaction and electronic coupling between inorganic nanosheet and hybridized species …”

“…In recent years, efforts have been devoted to the exploration of semiconductor photocatalysts, including CdS, ZnO, NiO, and Bi 2 WO 6 . To overcome the limitations of visible‐light absorption and reaction kinetics, many alternative methods have been reported to improve several key factors of such photocatalysts, e.g., enhanced absorptivity of visible light, increased lifetime of the photogenerated electrons and holes, and improved charge transport properties . One of the most efficient methods is the hybridization with other chemical species, such as oppositely charged inorganic 2D nanosheets.…”

“…As shown in Figure e, the intervention of a highly conductive nanosheet prevents the electron–hole recombination because this nanosheet attracts photogenerated charge species from the surrounding material by acting as a charge reservoir. As depicted in Figure f, the narrow‐bandgap semiconducting component can function as a light sensitizer in this hybrid system, even if it is not photocatalytically active …”