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[Display omitted] The emerging aqueous Zn-ion batteries (ZIBs) with their low price and inherent safety are showing strong competitiveness in the energy storage field. In this work, layer-by-layer stacked amorphous V 2 O 5 @Ti 3 C 2 T x heterostructures anchored on three-dimensional carbon cloth (3D CC), synthesized by annealing process and subsequent in-situ electrochemical induction, are reported as high capacity and stable cathode for ZIBs. In this composite cathode, amorphous V 2 O 5 @Ti 3 C 2 T x synergistic heterostructure provides isotropic Zn2+ migration channels and rapid electron transfer kinetics, while the 3D CC substrate can ensure that the bulk phase in the electrode material is also utilized to maximize the synergistic effect. As a result, the CC/a-V 2 O 5 @Ti 3 C 2 Ti x cathode achieves a high specific capacity of 567 mAh/g at 0.1 A/g, a satisfactory rate performance of 213 mAh/g at 10 A/g, together with a long cycle life of 96.2 % capacity retention after 2000 cycles. Ex-situ characterizations show that the CC/a-V 2 O 5 @Ti 3 C 2 T x cathode undergoes a highly reversible Zn2+/H+ co-intercalation/deintercalation mechanism during the discharge/charging process. In addition, based on the CC/a-V 2 O 5 @Ti 3 C 2 T x cathode, the assembled flexible ZIB can operate properly under different bending degrees, showing its practicality in flexible devices. This work provides insight into the rational design of cathode materials with high Zn-storage performance. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of efficient catalysts for hydrogen evolution reaction (HER) from water splitting is one of the most promising strategies to achieve the goal of peak carbon dioxide emissions and carbon neutrality. Herein, Ru nanoclusters decorated MoSe 2 nanosheets supported on a Crepis tectorum fluff biomass-derived hollow carbon tube (Ru-MoSe 2 /CMT) are prepared as the HER catalysts in both alkaline and acidic conditions. The Ru modification induces the transformation of MoSe 2 from 2H phase to 1T phase. Benefiting from the strong water dissociation ability of Ru, Ru-MoSe 2 /CMT exhibits a low overpotential of 70 mV with a Tafel slope of 39 mV dec-1 in 1 M KOH. Furthermore, the assembled Ru-MoSe 2 /CMT || RuO 2 system with a low cell voltage of 1.54 V at 10 mA cm−2 exhibits outstanding overall water splitting performance superior to Pt/C || RuO 2 system. The Ru-MoSe 2 /CMT || RuO 2 system also achieves the excellent stability of up to 30 h in 1 M KOH. The synergy effect between Ru and MoSe 2 , as well as the improved electron transfer kinetics provided by the biomass-derived carbon substrate together contribute to the excellent HER activity of Ru-MoSe 2 /CMT. [ABSTRACT FROM AUTHOR]

The Mo 2 C@C catalyst was prepared by the calcination method under the argon gas flow of the activated walnut shell-ammonium heptamolybdate hybrid powder mixture, enhancing the electrocatalytic hydrogen evolution process. • The waste walnut shell powder was chosen as the carbon source for HER catalysts. • The walnut shell powders derived carbon matrix can enhance the electron transfer. • The open pores can facilitate electrolyte permeation and hydrogen release. Herein, we choose the waste walnut shell as the carbon source, and ammonium heptamolybdate as the molybdenum source to prepare the β-Mo 2 C catalyst supported on carbon matrix (Mo 2 C@C) by the calcination method for hydrogen evolution reaction (HER). The open pores in the porous Mo 2 C nanoparticle clusters can facilitate electrolyte permeation and hydrogen molecules release as well as the carbon matrix can enhance the conductivity. As a result, the optimal Mo 2 C exhibits an efficient HER performance, with an overpotential of 140 mV at 10 mA cm−2 and a Tafel slope of 63 mV dec−1 as well as excellent electrochemical stability. The strategy changing waste walnut shell into the effective catalysts sets an example for the searching and designing rational energy materials. [ABSTRACT FROM AUTHOR]