Plasmonic Pt-PPCN/TiN Ohmic Junction for Photo-Thermo\nCatalytic Hydrogen Production

The\nrational design of photocatalysts for improving the conversion\nof solar energy into hydrogen is a promising route for achieving carbon\nneutrality. Herein, we couple plasmonic titanium nitride (TiN) with\nhighly crystalline potassium-doped polymeric carbon nitride (PPCN)\nto construct a PPCN/TiN ohmic junction. Such an ohmic junction not\nonly broadens the absorption spectrum but also inhibits the recombination\nof electrons and holes. In addition, Pt nanoparticles are introduced\ninto this ohmic junction to form plasmonic Pt-PPCN/TiN, improving\nthe capture of hot electrons generated by TiN and thereby promoting\nthe dissociation of the O–H bond in H<sub>2</sub>O. The energy\nbarrier decreases from 0.7 to 0.2 eV. Enhanced separation of carrier,\nactivation of water molecules, and capture of hot electrons are jointly\npromoting photo-thermo catalytic hydrogen production. Therefore, under\nfull-spectrum irradiation, the hydrogen production rate of Pt-PPCN/TiN\nreaches 19 085 μmol g<sup>–1</sup> h<sup>–1</sup>. This novel plasmonic photocatalyst is promising for full-spectrum\nphoto-thermo catalytic hydrogen production.