Dopant-controlled polysulfide anchoring on MoS2/graphene bilayers: insights from a complementary d-band-NMR descriptor framework.

Rational design of sulfur hosts for room-temperature sodium-sulfur batteries requires simultaneous control over polysulfide anchoring and redox kinetics, yet a unified descriptor linking electronic structure to interfacial behavior remains elusive. Here, we establish a descriptor-level framework that integrates d-band theory with nuclear magnetic resonance (NMR) signatures to elucidate dopant-controlled polysulfide interactions in MoS2/graphene bilayers. Using first-principles calculations, we show that heteroatom doping (B, P, and N) systematically modulates the Mo d-band center, governing the strength of Mo-S hybridization and interfacial charge transfer. These electronic perturbations are complemented by site-resolved NMR parameters, providing experimentally accessible fingerprints of local bonding environments and adsorption strength. We identify distinct dopant-dependent regimes: B doping promotes strong covalent hybridization and electronic activation, P doping achieves an optimal balance between adsorption and charge transport, and N doping induces pronounced charge localization and polarization. This unified descriptor framework consistently explains adsorption energetics, charge redistribution, and catalytic activity. Furthermore, dopant-induced electronic tuning lowers Na2S decomposition barriers, while selective dopants promote Na-ion diffusion, thereby accelerating redox kinetics. Our results demonstrate that the d-band center and NMR signatures act as complementary electronic descriptors that consistently explain polysulfide anchoring, charge redistribution, and catalytic activity, providing a generalizable strategy for designing electronically and chemically optimized sulfur hosts for advanced sodium-sulfur batteries.