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Rational design of electrode materials plays a significant role in potential applications such as energy storage and conversion. In this work, CoNi 2 S 4 /Ni 3 S 2 nanowires grown on Ni foam were synthesized through a facile hydrothermal approach, revealing a large capacitance of 997.2 F g -1 and cycling stability with 80.3% capacitance retention after 5000 cycles. The device was prepared using CoNi 2 S 4 /Ni 3 S 2 //AC as the positive electrode and active carbon as the negative electrode, and delivered an energy density of 0.4 mW h cm -3 at a power density of 3.99 mW cm -3 and an excellent cycle life with 79.2% capacitance retention after 10 000 cycles. In addition, the hybrid CoNi 2 S 4 /Ni 3 S 2 nanowires demonstrate excellent OER performance with low overpotential of 360 mV at 30 mA cm -2 and overpotential of 173.8 mV at -10 mA cm -2 for the HER, a cell voltage of 1.43 V, and excellent cycle stability., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Heterogeneity can be used as a promising method to improve the electrochemical performance of electrode materials; thus, ZnCo 2 O 4 @PPy samples were prepared using a facile hydrothermal route and an electrochemical deposition process. The as-prepared products possess a specific capacitance of 605 C g -1 at a current density of 1 A g -1 . The asymmetric supercapacitor (ASC) possesses an energy density of 141.3 W h kg -1 at a power density of 2700.5 W kg -1 and capacity retention of 88.1% after 10 000 cycles, indicating its promising potential for energy devices. ZnCo 2 O 4 @PPy-50 exhibited an excellent OER performance and outstanding HER performance in alkaline media. As an advanced bifunctional electrocatalyst for overall water splitting, a voltage of 1.61 V at a current density of 50 mA cm -2 outperforms the majority of noble-metal-free electrocatalysts., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)