A simple method is developed for the preparation of MoSe₂/MoO₂ composite with a flower-like structure for high-performance lithium-ion batteries (LIBs). MoSe₂ could lead to fast and facile movement of Li⁺ due to its larger interlayer spacing. Meanwhile, MoO₂ could protect the lamellar structure of MoSe₂ from being destroyed in the charging/discharging processes to maintain the required active surface to electrolytes. In addition, the flower-like structure of the composite could effectively alleviate the volume expansion during charging/discharging. As LIBs are anode material, MoSe₂/MoO₂ composite demonstrates an excellent specific discharge capacity of 1042 mAh g⁻¹ after 100 cycles at 0.1 A g⁻¹, which is attributed to the synergistic effects of MoSe₂ and MoO₂ in the composite.

Hybrid organic-inorganic perovskite materials have attracted extensive attention due to their impressive performance in photovoltaic devices. One-dimensional perovskite CH₃NH₃PbI₃ nanomaterials, possessing unique structural features such as large surface-to-volume ratio, anisotropic geometry and quantum confinement, may have excellent optoelectronic properties, which could be utilized to fabricate high-performance photodetectors. However, in comparison to CH₃NH₃PbI₃ thin films, reports on the fabrication of CH₃NH₃PbI₃ nanowires for optoelectrical application are rather limited. Herein, a two-step spin-coating process has been utilized to fabricate pure-phase and single-crystalline CH₃NH₃PbI₃ nanowires on a substrate without mesoporous TiO₂ or Al₂O₃. The size and density of CH₃NH₃PbI₃ nanowires can be easily controlled by changing the PbI₂ precursor concentration. The as-prepared CH₃NH₃PbI₃ nanowires are utilized to fabricate photodetectors, which exhibit a fairly high switching ratio of ~600, a responsivity of 55 mA/W, and a normalized detectivity of 0.5 × 10¹¹ jones under 532 nm light illumination (40 mW/cm²) at a very low bias voltage of 0.1 V. The as-prepared perovskite CH₃NH₃PbI₃ nanowires with excellent optoelectronic properties are regarded to be a potential candidate for high-performance photodetector application.

Heazlewoodite, Ni ₃ S ₂ , is one of the most promising bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media due to its metallic conductivity and low cost.

The development of earth-abundant and low-cost electrocatalysts with high performance toward the oxygen evolution reaction (OER) plays a key role in water splitting. Here, a novel OER electrocatalyst of Ni–Fe–OH/Ni₃S₂ nanoparticles on Ni foam (Ni–Fe–OH/Ni₃S₂/NF) was synthesized by a facile, ultrafast two-step method within 2 minutes. The obtained Ni–Fe–OH/Ni₃S₂/NF catalyst presents an excellent OER performance, only requiring a low overpotential of 268 mV to reach a current density of 10 mA cm⁻² and a small Tafel slope of 54 mV dec⁻¹ in 1 M KOH, which was sustained for 12 h at a current density of 175 mA cm⁻² almost without any degradation. The superior OER performance of the Ni–Fe–OH/Ni₃S₂/NF catalyst is attributed to the increased active sites, the accelerated electron transfer between the electrode and electrolyte, and the synergistic effect between amorphous Ni–Fe–OH and Ni₃S₂. This work opens up a new avenue for preparing highly efficient heterostructure electrocatalysts toward the OER.

In this paper, the synthesis of the three-dimensional (3D) composite of spherical reduced graphene oxide (RGO) with uniformly distributed CeO₂ particles is reported. This synthesis is done via a facile and large-scalable spray-drying process, and the CeO₂/RGO materials are hydrothermally compounded with sulfur. The morphology, composition, structure, and electrochemical properties of the 3D S/CeO₂/RGO composite are studied using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), Raman spectra and X-ray photoelectron spectroscopy (XPS), etc. The electrochemical performance of the composites as electrodes for lithium–sulfur batteries is evaluated. The S/CeO₂/RGO composites deliver a high initial capacity of 1054 mAh g⁻¹, and retain a reversible capacity of 792 mAh g⁻¹ after 200 cycles at 0.1 C. Profiting from the combined effect of CeO₂ and RGO, the CeO₂/RGO materials effectively inhibit the dissolution of polysulfides, and the coating of spherical RGO improves the structural stability as well as conductivity.

The development of stable and efficient electrocatalysts for oxygen evolution reaction is of great significance for electro-catalytic water splitting. Bimetallic layered double hydroxides (LDHs) are promising OER catalysts, in which NiCu LDH has excellent stability compared with the most robust NiFe LDH, but the OER activity is not satisfactory. Here, we designed a NiCu LDH heterostructure electrocatalyst (Cu/NiCu LDH) modified by Cu nanoparticles which has excellent activity and stability. The Cu/NiCu LDH electrocatalyst only needs a low over-potential of 206 mV and a low Tafel slope of 86.9 mV dec⁻¹ at a current density of 10 mA cm⁻² and maintains for 70 h at a high current density of 100 mA cm^–2 in 1M KOH. X-ray photoelectron spectroscopy (XPS) showed that there was a strong electronic interaction between Cu nanoparticles and NiCu LDH. Density functional theory (DFT) calculations show that the electronic coupling between Cu nanoparticles and NiCu LDH can effectively improve the intrinsic OER activity by optimizing the conductivity and the adsorption energy of oxygen-containing intermediates.