High‐performance supercapacitors have attracted great attention due to their high power, fast charging/discharging, long lifetime, and high safety. However, the generally low energy density and overall device performance of supercapacitors limit their applications. In recent years, the design of rational electrode materials has proven to be an effective pathway to improve the capacitive performances of supercapacitors. Layered double hydroxides (LDHs), have shown great potential in new‐generation supercapacitors, due to their unique two‐dimensional layered structures with a high surface area and tunable composition of the host layers and intercalation species. Herein, recent progress in LDH‐based, LDH‐derived, and composite‐type electrode materials targeted for applications in supercapacitors, by tuning the chemical/metal composition, growth morphology, architectures, and device integration, is reviewed. The complicated relationships between the composition, morphology, structure, and capacitive performance are presented. A brief projection is given for the challenges and perspectives of LDHs for energy research.

Evolution of heterogeneous catalysts with steady down-sizing: from small particles, clusters, dots to single atoms, and now the “surface heterocompound”.

Metal nanoparticles (NP) supported on TiO 2 are known to be efficient photocatalysts for solar-to-chemical energy conversion. While TiO 2 decorated with copper NPs has the potential to become an attractive system, the poor oxidative stability of Cu severely limits its applicability. In this work, we demonstrate that, when Cu NPs supported on TiO 2 nanobelts (NBs) are engaged in the photocatalytic generation of H 2 from water under light illumination, Cu is not only oxidized in CuO but also dissolved under the form of Cu + /Cu 2+ ions, leading to a continuous reconstruction of nanoparticles via Ostwald ripening. By nanoencapsulating the CuO x (Cu/CuO/Cu 2 O) NPs by a few layers of carbon supported on TiO 2 (TC@C), Ostwald ripening can be suppressed. Simultaneously, the resulting CuO x @C NPs are photoreduced under light illumination to generate Cu@C NPs. This photoswitching strategy allows the preparation of a Cu plasmonic photocatalyst with enhanced activity for H 2 production. Remarkably, the photocatalyst is even active when illuminated with visible light, indicating a clear plasmonic enhancement of photocatalytic activity from the surface plasmonic resonance (SPR) effect of Cu NPs. Three-dimensional electromagnetic wavefrequency domain (3D-EWFD) simulations were conducted to confirm the SPR enhancement. This advance bodes for the development of scalable multifunctional Cu-based plasmonic photocatalysts for solar energy transfer.