Bimetal-organic framework derived multi-heterostructured TiO2/CuxO/C nanocomposites with superior photocatalytic H2 generation performance

Abstract

In-situ formation of p-n heterojunctions between TiO2 and CuxO in heteroatoms-doped carbon nanocomposites and their applications in photocatalytic H2 evolution were demonstrated. One-step pyrolysis of bimetal-organic-frameworks NH2-MIL-125(Ti/Cu) in steam at 700 ºC forms phasejunction between nitrogen/carbon co-doped anatase and rutile, accompanied with formation of CuxO heterostructures. Moreover, p-n heterojunction is also formed between TiO2/CuxO nanoparticles that embedded in N-containing and hydrophilic carboxyl functionalized carbon. The optimized polymorph TiO2 phasejunction, CuxO heterostructure and p-n heterojunction between TiO2 and CuxO, together with functionalized carbon matrix offer multiple pathways for photoinduced electrons and holes migration, absorb more visible light and provide increased active sites for photocatalytic reactions. Without loading noble metals, TiO2/CuxO/C nanocomposite derived from 700 ºC in steam exhibited superior photocatalytic H2 generation activity of 3298 µmol gcat-1 h-1 under UV-Visible light, 40 times higher than commercial TiO2. This work offers a simple approach to novel photocatalytic nanocomposites for efficient H2 generation.