CoO with a high theoretical capacitance has been widely recognized as a promising electrode material for supercapacitor, but its poor electrical conductivity and stability limit its practical applications. Here, we developed an effective synthetic route to synthesize one-dimensional (1D) porous ZnO/CoO heterojunction composites. Benefiting from the heterostructure to promote the charge transfer and protect CoO from corrosion and the 1D porous structure to improve ion diffusion and prevent structural collapse in charge and discharge process, the as-prepared ZnO/CoO composites exhibited an excellent capacitive performance and good cycling stability. The specific capacitance of the ZnO/CoO-450 (1135 F g at 1 A g) was 1.4 times higher than that of CoO (814 F g), and the high-rate performance for ZnO/CoO-450 was 4.9 times better than that of CoO. Also, approximately 83% of its specific capacitance was retained after 5000 cycles at 10 A g. Most importantly, the as-fabricated asymmetric supercapacitor, with a ZnO/CoO-450 positive electrode and an activated carbon negative electrode, delivered a prominent energy density of 47.7 W h kg and a high power density of 7500 W kg. Thus, the ZnO/CoO composites could serve as a high-activity material for supercapacitor and the preparation method also offers an attractive strategy to enhance the capacitive performance of CoO.

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Metal sulfide semiconductors, such as molybdenum disulfide (MoS 2 ) and bismuth trisulphide (Bi 2 S 3 ), are of considerable interest for their excellent applications in photocatalysis and in many other fields. However, the controllable synthesis of MoS 2 /Bi 2 S 3 hybrid nanostructures remains a challenge. In this study, we report a unique sacrificial templating strategy for preparing layer-controlled MoS 2 on three-dimensional (3D) Bi 2 S 3 micro-flowers. For this approach, Bi 2 S 3 was utilized as a sacrificial template to regulate the ion exchange, and the dosage of molybdenum was adjusted to tune the dynamic formation, thus converting the MoS 2 nanosheets on the Bi 2 S 3 micro-flowers from monolayer to multilayer. Such a 3D flower-like hybrid nanostructure enables MoS 2 /Bi 2 S 3 to exhibit adsorption-promoted photocatalysis under visible light irradiation, especially for the excellent photodegradation of low-concentration organic pollutants, for example, azo dye and atrazine. The observed superiority of the 3D MoS 2 /Bi 2 S 3 was mainly attributed to the increased mass transfer, robust light-harvesting capacity, improved charge separation, lower oxygen-activation barrier and enhanced active oxygen yield. Our findings are of interest for the development of novel S-based photocatalysts and provide a new opportunity to efficiently remove low-concentration refractory pollutants.