ZnS nanowires/Cu₇S₄ nanoparticles/rGO nanocomposites were fabricated as photocatalysts and supercapacitor electrodes for the first time.

The exploitation of low-cost, efficient and stable electrocatalysts for overall water splitting in alkaline media is critical for future renewable energy systems, yet still remains a great challenge. Herein, we report the in situ growth of porous NiCoSe nanosheet arrays derived from 2D MOFs on Ni foam through a simple ion-exchange reaction followed by a hydrothermal process. Benefiting from the unique 2D multi-porous framework with high electrochemical active surface area, conductivity and open channels for the release of gaseous products, the as-prepared NiCoSe nanosheet arrays exhibit excellent electrochemical activity with a low overpotential of 170 mV for the hydrogen evolution reaction (HER) at 10 mA cm⁻² and 278 mV for the oxygen evolution reaction (OER) at 20 mA cm⁻² and long-term stability. Furthermore, the full cell only requires 1.51 V to drive the current density of 10 mA cm⁻² when the NiCoSe nanosheet arrays are used as both anode and cathode, which also exhibits distinguished durability for over 48 h. The present work presents a general strategy for the rational design and synthesis of multifunctional 2D porous electrocatalysts, which is also expected to extend to other noble-metal-free catalysts.

ZnS nanowires (NWs)–graphene (GR) nanocomposites were successfully synthesized via an easy electrostatic self-assembly method. The results showed that ZnS NWs were well dispersed on the surface of the graphene nanosheets, forming ZnS–GR nanocomposites. The photoluminescence intensity of the ZnS–GR nanocomposites exhibited a clear quenching in comparison with that of the ZnS NWs. The ZnS–GR nanocomposites were used as photocatalysts for the degradation of methylene blue (MB) under UV light irradiation. After irradiation for 1 h, the degradation efficiency was 21.69% for ZnS NWs, 31.52% for ZnS–0.5 wt% GR, 58.69% for ZnS–3 wt% GR, 88.33% for ZnS–5 wt% GR and 80.74% for ZnS–7 wt% GR, indicating that ZnS–5 wt% GR nanocomposites had the highest photocatalytic activity. The kinetic rate constant of the ZnS–5 wt% GR nanocomposites was about 16 times higher than that of the ZnS NWs. The mechanism of the highly enhanced photocatalytic properties was attributed to the efficient separation of the photogenerated electron–hole pairs and the high specific surface area of graphene.

Representing single-layer to tens of layers of graphene in a size less than 30 nm, carbon quantum dots (CQDs) is becoming an advanced multifunctional material for its unique optical, electronic, spin and photoelectric properties induced by the quantum confinement effect and edge effect. In present work, upon co-doping engineering, nitrogen and chlorine co-doped CQDs with uniquely strong blue-green double emissions are developed via a facile and one-pot hydrothermal method. The crystalline and optical properties of CQDs have been well manipulated by tuning the mole ratio of nitrogen/chlorine and the reaction time. The characteristic green emission centered at 512 nm has been verified, originating from the chlorine-related states, the other blue emissions centered at 460 nm are attributed to the conjugated π-domain. Increasing the proportion of 1,2,4-benzentriamine dihydrochloride can effectively adjust the bandgap of CQDs, mainly caused by the synergy and competition of chlorine-related states and the conjugated π-domain. Prolonging the reaction time promotes more nitrogen and chlorine dopants incorporate into CQDs, which inhibits the growth of CQDs to reduce the average size of CQDs down to 1.5 nm, so that the quantum confinement effect dominates into play. This work not only provides a candidate with excellent optical properties for heteroatoms-doped carbon materials but also benefits to stimulate the intensive studies for co-doped carbon with chlorine as one of new dopants paradigm.

The morphology evolution and electrochemical properties of Ni_0.85Se via Fe doping were investigated for overall water splitting and supercapacitors.

Doping Cu ²⁺ and Mn ²⁺ ions into Zn _1−x Cd _x S NRs makes the samples exhibit a strong emission at 509.6 and 583 nm.