Sulfur-source-dependent phase-selective preparation of Cu3NiInSnS6 nanocrystals and their optical and magnetic properties.

Multifunctional multinary metal chalcogenides have long been a research hotspot in the field of materials chemistry due to their rich composition, flexible structure, excellent properties and wide range of applications. However, the exploration of complex quinary chalcogenides is still challenging. In this work, for the first time, we have developed the controlled synthesis of quinary Cu3NiInSnS6 nanocrystals, realizing the selective preparation of hexagonal wurtzite and cubic zinc blende metastable phases by simply tuning the sulfur source. The phase structure analysis reveals that both metastable phases possess a disordered structure with a random distribution of metal atoms in the unit cells. The fabricated wurtzite and zinc blende-structure Cu3NiInSnS6 nanocrystals have a direct band gap of 1.82 and 1.94 eV, respectively, and both exhibit superparamagnetic behavior at low temperatures. This work is of great significance for the development of novel multifunctional materials based on metastable multinary metal chalcogenide phases.

Self-supported electrode based on two-dimensional NiPS3 for supercapacitor application.

Two-dimensional (2D) layered materials hold great promise for electrochemical energy storage due to their unique structure. It is always desirable to explore new-type high-performance 2D structured electrode materials in energy field. In this work, layered transition-metal chalcogenophosphite is developed as the electrode material for supercapacitors for the first time. NiPS3 nanosheet arrays are successfully in-situ grown on carbon cloth via a chemical vapor deposition method, and then directly used as the self-supported electrode for supercapacitors. The fabricated carbon cloth supported NiPS3 nanosheet arrays offer obviously superior electrochemical performance to the powdery NiPS3 nanosheets sample. The self-supported NiPS3 electrode exhibits a high specific capacitance of 1148F g-1 at a current density of 1 A g-1, and a good cycling stability with capacitance retention of 81.4% over 5000 cycles at 10 A g-1. Moreover, the assembled asymmetric supercapacitor device delivers a specific capacitance of 61.3F g-1 at a current density of 1 A g-1, and an energy density of 19.2 Wh kg-1 at a power density of 750 W kg-1 with a voltage window of 1.5 V. This work is of great significance for pioneering the application of 2D transition-metal chalcogenophosphites in supercapacitors.