Facile Synthesis of Hierarchical Cu₂MoS₄ Hollow Sphere/Reduced Graphene Oxide Composites with Enhanced Photocatalytic Performance

We present a controllable synthesis of ternary hierarchical hollow sphere, assembling by numerous particle-like Cu₂MoS₄, via a facile hydrothermal method. By adding graphene oxides (GO) in the reaction process, Cu₂MoS₄/reduced graphene oxide (RGO) heterostructures were obtained with enhanced photocurrent and photocatalytic performance. As demonstrated by electron microscopy observations and X-ray characterizations, considerable interfacial contact was achieved between hierarchical Cu₂MoS₄ hollow sphere and RGO, which could facilitate the separation of photoinduced electrons and holes within the hybrid structure. In comparison with the pure Cu₂MoS₄ hollow sphere, the obtained hybrid structures exhibited significantly enhanced light absorption property and the ability of suppressing the photoinduced electron–holes recombination, which led to significant enhancement in both photocurrent and efficiency of photocatalytic methyl orange (MO) degradation under visible light (λ > 420 nm) irradiation

Stable 1T-MoSe₂ and Carbon Nanotube Hybridized Flexible Film: Binder-Free and High-Performance Li-Ion Anode

Two-dimensional stable metallic 1T-MoSe₂ with expanded interlayer spacing of 10.0 Å <i>in situ</i> grown on SWCNTs film is fabricated <i>via</i> a one-step solvothermal method. Combined with X-ray absorption near-edge structures, our characterization reveals that such 1T-MoSe₂ and single-walled carbon nanotubes (abbreviated as 1T-MoSe₂/SWCNTs) hybridized structure can provide strong electrical and chemical coupling between 1T-MoSe₂ nanosheets and SWCNT film in a form of C–O–Mo bonding, which significantly benefits a high-efficiency electron/ion transport pathway and structural stability, thus directly enabling high-performance lithium storage properties. In particular, as a flexible and binder-free Li-ion anode, the 1T-MoSe₂/SWCNTs electrode exhibits excellent rate capacity, which delivers a capacity of 630 mAh/g at 3000 mA/g. Meanwhile, the strong C–O–Mo bonding of 1T-MoSe₂/SWCNTs accommodates volume alteration during the repeated charge/discharge process, which gives rise to 89% capacity retention and a capacity of 971 mAh/g at 300 mA/g after 100 cycles. This synthetic route of a multifunctional MoSe₂/SWCNTs hybrid might be extended to fabricate other 2D layer-based flexible and light electrodes for various applications such as electronics, optics, and catalysts

Electron-Doped 1T-MoS₂ via Interface Engineering for Enhanced Electrocatalytic Hydrogen Evolution

Designing advanced electrocatalysts for hydrogen evolution reaction is of far-reaching significance. Active sites and conductivity play vital roles in such a process. Herein, we demonstrate a heteronanostructure for hydrogen evolution reaction, which consists of metallic 1T-MoS₂ nanopatches grown on the surface of flexible single-walled carbon nanotube (1T-MoS₂/SWNT) films. The simulated deformation charge density of the interface shows that 0.924 electron can be transferred from SWNT to 1T-MoS₂, which weakens the absorption energy of H atom on electron-doped 1T-MoS₂, resulting in superior electrocatalytic performance. The electron doping effect via interface engineering renders this heteronanostructure material outstanding hydrogen evolution reaction (HER) activity with initial overpotential as small as approximately 40 mV, a low Tafel slope of 36 mV/dec, 108 mV for 10 mA/cm², and excellent stability. We propose that such interface engineering could be widely used to develop new catalysts for energy conversion application