In this study, the effects of the solvent used to prepare Co–B alloy on its catalytic properties were investigated. The solvent effects on the morphology, composition, and specific surface area of the alloy particles were also examined. The morphology of the alloy particles was found to be dependent on the solvent. The particles were granular in water, methanol, and acetone, although the particle diameters differed, whereas they were nanoflake-like in acetonitrile. Acetonitrile produced the largest surface area of the alloy particles, but the lowest catalytic activity for the hydrolysis of NaBH₄ owing to the ready oxidation of the particles in air. The Co–B in acetone exhibited the highest catalytic activity, represented by a hydrogen generation rate of 5733 mL·min⁻¹·g⁻¹ during the hydrolysis of 1.5 wt % NaBH₄ at 298 K. This hydrogen generation rate is more than twice that produced by the Co–B in water.

In this study, polypyrrole (PPy) nanofibers were used to synthesize a super-activated carbon material. A highly-dispersed Co-Ni-B catalyst was supported on PPy nanofiber-derived activated carbon (PAC) by chemical reduction. The Co-Ni-B/PAC hybrid catalyst exhibited excellent catalytic performance for the decomposition of ammonia borane (AB) in an aqueous alkaline solution at room temperature. The size of the metal particles, morphology of Co-Ni-B/PAC, and catalytic activity of the supported catalyst were investigated. Ni-B, Co-B, and Co-Ni-B catalysts were also synthesized in the absence of PAC under similar conditions for comparison. The maximum hydrogen generation rate (1451.2 mL⁻¹·min⁻¹·g⁻¹ at 25 °C) was obtained with Co-Ni-B/PAC. Kinetic studies indicated that the hydrolysis reaction of AB was first order with respect to Co-Ni-B/PAC, and the activation energy was 30.2 kJ·mol⁻¹. Even after ten recycling experiments, the catalyst showed good stability owing to the synergistic effect of Co-Ni-B and PAC.

Phase change materials (PCMs) are widely used to improve energy utilization efficiency due to their high energy storage capacity. In this study, double-shell microencapsulated PCMs were constructed to resolve the liquid leakage issue and low thermal conductivity of organic PCMs, which also possess high thermal stability and multifunctionality. We used assembly to construct an inorganic–organic double shell for microencapsulate PCMs, which possessed the unprecedented synergetic properties of a cadmium sulfide (CdS) shell and melamine–formaldehyde polymeric shell. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the well-designed double-shell structure of the microcapsules, and the CdS was successfully assembled as the second shell on the surface of the polymer shell. The differential scanning calorimeter (DSC) showed that the double-shell microcapsules had a high enthalpy of 114.58 J/g, which indicated almost no changes after experiencing 100 thermal cycles, indicating good thermal reliability. The microcapsules also showed good shape stability and antileakage performance, which displayed no shape change and leakage after heating at 60 °C for 30 min. In addition, the photothermal conversion efficiency of the double-shell microcapsules reached 91.3%. Thus, this study may promote the development of microencapsulated PCMs with multifunctionality, offering considerable application prospects in intelligent temperature management for smart textiles and wearable electronic devices in combination with their solar thermal energy conversion and storage performance.