| Along with the rapid development of modern industry, the energy andenvironmental crisis has risen to a global problem. The development of new materialswith excellent performance plays the key factor to solve these problems. It’s knownthat material properties rely on their composition, structure and morphology. So thepreparation of novel material with excellent morphology and desired component hasbeen attracted increasing attentions. Cu/Ni-based chalcogenide, as importantsemiconductor material, have excellent catalytic, optical, electrochemicalperformance and prospect future in environmental protection, energy conversion andstorage. In this paper, a simple and mild method will be designed to achieve thepurposeful change of material component, morphology genetic, tuning of materialperformance, and finally make contributions to deal with energy and environmentalissues.Firstly, novel hierarchical wool-ball-like copper sulfide (CuS) microflowers witha three-dimensional (3D) porous framework were successfully synthesized by thedirect reaction of copper with sulfur powder using a one-pot in-situ growth methodunder low temperature (60oC). The CuS microflowers covered firmly the surface ofthe3D porous framework. The formation mechanism was examined in detail byadjusting the amount of hydrochloric acid and reaction time. Most importantly, thechemical composition of the CuS microflowers was altered by the Se exchangewithout changing its morphology and structure. In this way, pure CuSe and Cu1.8Secrystalline materials were obtained on the surface of the porous microtube underdifferent reaction time and the appropriate amount of Se powder. And interestingly,the core material remained to be CuS. This behavior greatly affects the physical andchemical properties of the materials. The catalytic ability of the as-obtainedCuSe@CuS and CuSe1.8@CuS composite materials to degrade methylene blue andrhodamine B are several times greater than that of the as-synthesized CuSmicroflowers.Secondly, novel hierarchical rose-like Cu1.8Se microspheres with a porous three-dimensional (3D) framework were successfully synthesized by using a one-potin situ growth method at a low temperature (60°C). The Cu1.8Se microspherescovered the surface of the3D porous framework. The formation mechanism wasinvestigated in detail by adjusting the volume ratio of DMF and EDA as the blendsolvents and the reaction time. Then, the chemical composition of the Cu1.8Semicrospheres was altered by the Ag+exchange without changing their morphologyand structure. In this way, the binary Cu1.8Se was efficiently converted into theternary CuAgSe. Notably, the band gap of materials was tuned continuously from3.83eV to3.03eV and CuAgSe was produced continuously by adjusting thereplacement time. This work provides a novel concept and a simple method that canserve as a good reference for the improving the performance of tunable materials andthe preparation of multielement alloy materials.At last, a novel method was successfully designed to achieve the purposefuladjustment of material composition with morphology genetic, also improve theelectrochemical performance of electrode material for supercapacitors. First, anest-like NiS@Ni3S2composite electrode with a1D nanorod as the structure unit wassynthesized by simultaneously using Ni foam as the template and Ni as the source viaone-step in situ growth method. Co and Se ions, which were the beneficial cation andanion, respectively, were successfully introduced into the nest-like NiS@Ni3S2material, which resulted in the formation of Co9S8@Ni3S2and NiSe2@NiS compositeelectrodes with structures similar to those of the parent materials. The structure ofmaterials was almost maintained, and the single-crystal-to-single-crystaltransformation was achieved in the process. Introducing the cation and anion into thesame type of material with morphology genetic is a major breakthrough in the field ofmaterial synthesis and in the preparation of supercapacitor electrodes. Moreover, theelectrochemical property of these three materials was also studied via cyclicvoltammetry (CV) measurements and galvanostatic charge-discharge tests, whichindicate the rate performance improved significantly by ion exchange, especially, thederived electrode with Se still showed the superior ability of oxidation and reductionat high scan rate of10000mV s-1. And the second charge-discharge specific capacityalso increased from516F g-1to925F g-1and1412F g-1at the current density of0.5 A g-1by Co and Se exchange, respectively. This work contributes to the knowledgeon electrode materials for supercapacitors and can be a good reference for thefabrication of desired materials. |
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