Multi-Elemental Electronic Coupling for Enhanced Hydrogen Generation

A robust polyaniline-assisted strategy is developed to construct a self-supported electrode constituting a nitrogen, phosphorus, sulfur tri-doped thin graphitic carbon layer encapsulated sulfur-doped molybdenum phosphide nanosheet array (NPSCL@S-MoP NSs/CC) with accessible nanopores, desirable chemical compositions, and stable composite structure for efficient hydrogen evolution reaction (HER). The multiple electronic coupling effects of S-MoP with N, P, S tri-dopants afford effective regulation on their electrocatalytic performance by endowing abundant accessible active sites, outstanding charge-transfer property, and d-band center downshift with a thermodynamically favorable hydrogen adsorption free energy (Delta G(H*)) for efficient hydrogen evolution catalysis. As a result, the NPSCL@S-MoP NSs/CC electrode exhibits overpotentials as low as 65, 114, and 49 mV at a geometric current density of 10 mA cm(-2) and small Tafel slopes of 49.5, 69.3, and 53.8 mV dec(-1) in 0.5 m H2SO4, 1.0 m PBS, and 1.0 m KOH, respectively, which could maintain 50 h of stable performance, almost outperforming all MoP-based catalysts reported so far. This study provides a valuable methodology to produce interacted multi-heteroatomic doped graphitic carbon-transition metal phosphide electrocatalysts with superior HER performance in a wide pH range.

Automated summary

A robust polyaniline-assisted strategy is developed to construct a self-supported electrode with nitrogen, phosphorus, sulfur tri-doped graphitic carbon layer encapsulated sulfur-doped molybdenum phosphide nanosheet array for efficient hydrogen evolution reaction. The electrode exhibits low overpotentials in different electrolytes and maintains stable performance for 50 hours, outperforming previous MoP-based catalysts.