Hierarchically organized porous carbonized‐Co3O4 inverse opal nanostructures (C‐Co3O4 IO) are synthesized via complementary colloid and block copolymer self‐assembly, where the triblock copolymer Pluronic P123 acts as the template and the carbon source. These highly ordered porous inverse opal nanostructures with high surface area display synergistic properties of high energy density and promising bifunctional electrocatalytic activity toward both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). It is found that the as‐made C‐Co3O4 IO/Ketjen Black (KB) composite exhibits remarkably enhanced electrochemical performance, such as increased specific capacity (increase from 3591 to 6959 mA h g−1), lower charge overpotential (by 284.4 mV), lower discharge overpotential (by 19.0 mV), and enhanced cyclability (about nine times higher than KB in charge cyclability) in Li–O2 battery. An overall agreement is found with both C‐Co3O4 IO/KB and Co3O4 IO/KB in ORR and OER half‐cell tests using a rotating disk electrode. This enhanced catalytic performance is attributed to the porous structure with highly dispersed carbon moiety intact with the host Co3O4 catalyst.

The use of graphene in conventional plasmonic devices was suggested by several theoretic research studies. However, the existing theoretic studies are not consistent with one another and the experimental studies are still at the initial stage. To reveal the role of graphenes on the plasmonic sensors, we deposited graphene oxide (GO) and reduced graphene oxide (rGO) thin films on Au films and their refractive index (RI) sensitivity was compared for the first time in SPR-based sensors. The deposition of GO bilayers with number of deposition L from 1 to 5 was carried out by alternative dipping of Au substrate in positively- and negatively charged GO solutions. The fabrication of layer-by-layer self-assembly of the graphene films was monitored in terms of the SPR angle shift. GO-deposited Au film was treated with hydrazine to reduce the GO. For the rGO-Au sample, 1 bilayer sample showed a higher RI sensitivity than bare Au film, whereas increasing the rGO film from 2 to 5 layers reduced the RI sensitivity. In the case of GO-deposited Au film, the 3 bilayer sample showed the highest sensitivity. The biomolecular sensing was also performed for the graphene multilayer systems using BSA and anti-BSA antibody.

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In recent years, a promising role of plasmonic metal nanoparticles (NPs) has been demonstrated toward an improvement of the catalytic efficiency of well‐designed hybrid electrocatalysts. In particular, the coupling of plasmonic functionality with the metal‐based core–shell architectures in plasmon‐enhanced electrocatalysis provides a sustainable route to improve the catalytic performances of the catalysts. Herein, the rationally designed AuNPs wrapped with reduced graphene oxide (rGO) spacer along with PdNPs (AuNP@rGO@Pd) as the final composite are reported. The rGO is proposed to promote the reduction of PdO, greatly enhance the conductivity, and catalytic activity of these nanohybrid structures. The plasmon‐enhanced electrocatalytic performance of optimized AuNP@rGO(1)@Pd exhibits an ≈1.9‐ and 1.1‐fold enhanced activity for the hydrogen evolution reaction and oxygen evolution reaction, respectively. The final composite also exhibits a superior stability up to 10000 s compared with the commercial Pd/C. The mechanism of the enhanced catalytic performance is monitored through in situ X‐ray absorption spectroscopy by observing the generated electron density under light irradiation. The results demonstrate that the energetic charge carriers are concentrated in the incorporated PdNPs, allowing higher catalytic performances for the overall water‐splitting reaction. The conclusions herein drawn are expected to shed light on upcoming plasmon‐induced electrocatalytic studies with analogous hybrid nanoarchitectures.

In recent years, the electroreduction of CO2 to valuable products has emerged as a rational answer to rising CO2 emissions and a strategic approach to incorporate renewable electricity from intermittent sources (e.g., wind and solar) into the global energy supply. The reduction of CO2 to CO has been highlighted in the widely explored industrial conversion of syngas (CO and H2) to fuels. Herein, we report a promising electrocatalyst incorporating well-dispersed gold nanoparticles (Au NPs) on ultrathin titanate nanosheets (TiNS). By tuning the contents of Au (in the ranges of 0 to 93 wt % Au) in the hybrid Au/TiNS architecture, CO product selectivity was effectively controlled (in the range of CO Faradaic efficiency from 3 to over 80%) with the sole additional formation of H2, which is of pronounced industrial interest. Most importantly, a control of both component amounts was suggested to result in a variation of corresponding electronic properties based on the interaction between Au NP and TiNS substrate, dictating the stabilization of formed reaction intermediates and resulting product selectivity. In addition, our Au/TiNS achieved optimally high CO and H2 production current densities, with 73 wt % Au at the low cathodic potential region (−0.6 to −0.9 VRHE). The suggested synergetic effect between both catalytic components underlines the promising character of this hybrid system and is expected to significantly add to the strategic production of syngas for subsequent applications.