No abstract

Hydrogen spillover (HSo) has emerged to upgrade the hydrogen evolution reaction (HER) activity of Pt‐support electrocatalysts, but it is not applicable to the deprotonated oxygen evolution reaction (OER). Non‐precious catalysts that can perform well in both HSo and deprotonation (DeP) are extremely desirable for a sustainable hydrogen economy. Herein, an affordable MoS2/NiPS3 vertical heterostructure catalyst is presented to synergize HSo and DeP for efficient water electrolysis. The internal polarization field (IPF) is clarified as the driving force of HSo in HER electrocatalysis. The HSo from the MoS2 edge to NiPS3 can activate the NiPS3 basal plane to boost the HER activity of the MoS2/NiPS3 heterostructure (112 mV vs reversible hydrogen electrode (RHE) at 10 mA cm–2), while for OER, the IPF in the heterostructure can facilitate the hydroxyl diffusion and render MoS2‐to‐NiPS3/P‐to‐S dual‐pathways for DeP. As a result, the stacking of OER‐inactive MoS2 on the NiPS3 surface still brings intriguing OER enhancements. With them serving as electrode couples, the overall water splitting is attested stably with a cell voltage of 1.64 V at 10 mA cm−2. This research puts forward the IPF as the criterion in the rational design of HSo/DeP‐unified non‐precious catalysts for efficient water electrolysis.

The utility of carbonaceous materials for hybrid semiconductor photocatalysts has been rapidly increasing in recent years due to the synergetic effect via interfacial charge transfer reactions. In this study, we prepared a novel graphdiyne–ZnO nanohybrid by the hydrothermal method and examined its photocatalytic properties on the degradation of two azo dyes (methylene blue and rhodamine B). Interestingly, the graphdiyne–ZnO nanohybrids showed superior photocatalytic properties than that of the bare ZnO nanoparticles as evidenced by the absorption spectra and total organic carbon analyses. Moreover, the rate constant of graphdiyne–ZnO nanohybrids is nearly 2-fold higher compared to that of the bare ZnO nanoparticles on the photodegradation of both azo dyes. Further, a plausible mechanism for the enhanced photocatalytic properties of the graphdiyne–ZnO nanohybrids has been discussed. This work on the development of graphdiyne-based semiconductor photocatalysis can provide new insights into the design of novel hybrid photocatalysts for potential applications in the environmental remediation sectors.

We rationalize how fluorite‐structured CeO2, which is crystallographically isotropic, can grow anisotropically (without templates) to form nanoparticles, rods, and cubes. In particular, single‐crystalline and monodispersed cubic CeO2 nanoparticles, nanorods, and nanocubes have been selectively synthesized by a very simple, efficient, and economical hydrothermal process using different NaOH concentrations, and Ce(NO3)3 as the cerium precursor. High‐resolution transmission electron microscopy reveals nanomaterials with differently exposed crystal planes: {111} and {100} for nanoparticles, {110} and {100} for nanorods, and {100} for nanocubes. During the preparation of the CeO2 nanomaterials, the formation of intermediate anisotropic Ce(OH)3 species under basic conditions and their conversion into CeO2 at higher temperature are key factors responsible for the shape evolution. Atomistic computer simulations were used to help rationalize how the synthetic conditions impact upon the morphology of the nanomaterial. The synthesized CeO2 nanoparticles and nanorods demonstrate higher catalase mimetic activities than the nanocubes.