Hierarchical ZnS-doped La 2 S 3 /rGO heterostructures for high-performance advanced supercapacitors

Multivalent sulfide redox activity was integrated with a highly conductive graphene framework in ZnS-doped La 2 S 3 /rGO heterostructures, accelerating charge-transfer kinetics and enhancing electrochemical utilization. This rationally engineered heterointerface design effectively mitigates the intrinsically low conductivity of rare-earth sulfides, enabling high-performance supercapacitor (SC) electrodes. A hierarchical multicomponent nanocomposite was prepared by a hydrothermal route: ZnS-doped La 2 S 3 (LaS) nanoarrays grown on reduced graphene oxide (ZnGLaS), together with control samples of pristine LaS and ZnS-doped La 2 S 3 (ZnLaS). The interconnected ZnGLaS heterostructure builds a high-surface-area network that supplies abundant electroactive sites and short ion/electron pathways, boosting Faradaic redox activity. The conductive rGO scaffold and strong interfacial coupling accelerate charge-transfer kinetics. Benefiting from this synergistic architecture, the freestanding ZnGLaS electrode delivers a specific capacitance of 1776.26Formula: see textFFormula: see textgFormula: see text at 1Formula: see textAFormula: see textgFormula: see text, an energy density (Ed) of 61.6Formula: see textWhFormula: see textkgFormula: see text at 1Formula: see textAFormula: see textgFormula: see text, and a power density of 1911.9Formula: see textWFormula: see textkgFormula: see text, while retaining 94.57% capacitance after 8000 cycles. As an asymmetric supercapacitor (ASC) paired with activated carbon (ZnGLaS//AC), the device achieves 1338.83Formula: see textFFormula: see textgFormula: see text at 1Formula: see textAFormula: see textgFormula: see text and 86Formula: see textWhFormula: see textkgFormula: see text, sustaining 86.84% capacitance retention after 8000 cycles. These results demonstrate a cost-effective path to high-performance heterostructured SCs.