Hollow carbon nanoboxes with FeSe2/CoSe2 heterojunctions via MOF-on-MOF engineering for efficient energy conversion

The simultaneous optimization of electronic structure and nanoscale architecture to boost interfacial electron transfer and tune active site electronic configuration remains pivotal for advancing high-efficiency carbon-based electrocatalysts. Herein, we propose a MOF-on-MOF interface engineering strategy to engineer 3D nitrogen-modified carbon nanoboxes embedded with FeSe₂/CoSe₂ heterostructures (FeSe₂/CoSe₂@NMCN). The hierarchical architecture integrates hollow morphology with multi-level porosity, establishing efficient charge transport pathways. Crucially, heterointerface-induced built-in electric fields modulate d-band centers through interfacial charge redistribution, achieving optimized adsorption energy of the catalytic reaction intermediates. FeSe₂/CoSe₂@NMCN loaded on a nickel foam electrode demonstrates exceptional hydrogen evolution reaction (HER) performance with ultra-low overpotentials of 96 mV (10 mA cm⁻²) and 198 mV (100 mA cm⁻²). Assembled photovoltaic devices achieve remarkable 8.14 % (AM 1.5G) and 16.80 % (3000 lux indoor) power conversion efficiencies during triiodide reduction reaction (IRR). Density functional theory (DFT) calculations further revealed strong electronic interactions at the FeSe₂/CoSe₂ heterointerface following optimization of the electronic structure of the catalyst, which can enhance adsorption capacities for reaction intermediates. This work establishes a morphology-electronic dual-regulation strategy through heterostructure and nano-confinement effects, providing data and theoretical support into novel catalyst design for sustainable energy systems.