Unveiling the Synergistic Role of Frustrated Lewis Pairs in Carbon-Encapsulated Ni/NiO x Photothermal Cocatalyst for Enhanced Photocatalytic Hydrogen Production

The development of high-density and closely spaced frustrated Lewis pairs (FLPs) is crucial for enhancing catalyst activity and accelerating reaction rates. However, constructing efficient FLPs by breaking classical Lewis bonds poses a significant challenge. Here, this work has made a pivotal discovery regarding the Jahn-Teller effect during the formation of grain boundaries in carbon-encapsulated Ni/NiOx (Ni/NiO @C). This effect facilitates the formation of high-density O (V ) and Ni (V ) vacancy sites with different charge polarities, specifically FLP-V -C basic sites and FLP-V -C acidic sites. The synergistic interaction between FLP-V -C and FLP-V -C sites not only reduces energy barriers for water adsorption and splitting, but also induces a strong photothermal effect. This mutually reinforcing effect contributes to the exceptional performance of Ni/NiO @C as a cocatalyst in photothermal-assisted photocatalytic hydrogen production. Notably, the Ni/NiO @C/g-C N (NOCC) composite photocatalyst exhibits remarkable hydrogen production activity with a rate of 10.7 mmol g h , surpassing that of the Pt cocatalyst by 1.76 times. Moreover, the NOCC achieves an impressive apparent quantum yield of 40.78% at a wavelength of 380 nm. This work paves the way for designing novel defect-state multiphase cocatalysts with high-density and adjacent FLP sites, which hold promise for enhancing various catalytic reactions.