Gold nanoparticles are frequently employed as nanozyme materials due to their capacity to catalyze various enzymatic reactions. Given their plasmonic nature, gold nanoparticles have also found extensive utility in chemical and photochemical catalysis owing to their ability to generate excitons upon exposure to light. However, their potential for plasmon-assisted catalytic enhancement as nanozymes has remained largely unexplored due to the inherent challenge of rapid charge recombination. In this study, we have developed a strategy involving the encapsulation of gold nanorods (AuNRs) within a titanium dioxide (TiO₂) shell to facilitate the efficient separation of hot electron/hole pairs, thereby enhancing nanozyme reactivity. Our investigations have revealed a remarkable 10-fold enhancement in reactivity when subjected to 530 nm light excitation following the introduction of a TiO₂ shell. Leveraging single-molecule kinetic analyses, we discovered that the presence of the TiO₂ shell not only amplifies catalytic reactivity by prolonging charge relaxation times but also engenders additional reactive sites within the nanozyme's intricate structure. We anticipate that further enhancements in nanozyme performance can be achieved by optimizing interfacial interactions between plasmonic metals and semiconductors.

Synthesis of nitrogen doped mesoporous graphitic carbon spheres with dispersed metal oxide nanoparticles using a single temperature treatment step serves as one of the big challenges in materials research. To date only a few reports have been published on the soft-templating synthesis of mesoporous graphitic carbons. The preparation of graphitic carbons with dispersed Fe₂O₃ using a single carbonization step at relatively low temperatures is yet to be explored. The first phase of this work shows the potential of graphitization of polyvinylpyrrolidine (PVP) stabilized cubic Prussian blue nanoparticles (CPB) in phenolic resin spheres to produce graphitic carbon spheres through a facile Stöber-like method. In the second phase, the Pluronic F127 soft template was used along with PVP stabilized Prussian blue nanoparticles (PB) in carbon spheres to generate mesopores and graphitic domains with uniformly dispersed Fe₂O₃ nanoparticles in these spheres. Due to the presence of graphitic layers, doped N species and Fe₂O₃ nanoparticles in the carbon matrix, the yielded carbon spheres feature a high surface area and magnetic properties. Moreover, these graphitic spheres exhibited excellent capacitive behavior with rectangular cyclic voltammetry (CV) profiles and large capacitance up to 247 F g⁻¹ at 1 mV s⁻¹ scan rate in 6 M KOH solution.