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 1776.26[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], an energy density (Ed) of 61.6[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], and a power density of 1911.9[Formula: see text]W[Formula: see text]kg[Formula: see text], while retaining 94.57% capacitance after 8000 cycles. As an asymmetric supercapacitor (ASC) paired with activated carbon (ZnGLaS//AC), the device achieves 1338.83[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text] and 86[Formula: see text]Wh[Formula: see text]kg[Formula: see text], sustaining 86.84% capacitance retention after 8000 cycles. These results demonstrate a cost-effective path to high-performance heterostructured SCs.