Enhanced photocatalytic hydrogen production over conjugated polymer/black TiO2 hybrid: The impact of constructing active defect states

Abstract Utilization of noble metal (e.g. Pt, Au) as co-catalyst seems always indispensable for a photocatalytic H 2 production catalyst because most semiconductors lack sufficient active sites. Herein, some non-noble metal active states, Ti 3+ /Ov (oxygen vacancies) and surface amorphization structure, are introduced into anatase TiO 2 nanoparticles by ball milling them with TiH 2 to prepare black TiO 2 . And then, an organic/inorganic hybrid (BE-black TiO 2 ) containing a conjugated polymer (BE, a modified poly- benzothiadiazole flake) and black TiO 2 is fabricated and investigated for photocatalytic H 2 production without noble metal co-catalyst. Compare to BE-TiO 2 catalyst, the BE-black TiO 2 exhibit a ∼ 30% enhancement for H 2 production activity under visible light (λ > 420 nm) irradiation. Combining the structural characterizations, comparison of H 2 production rate and electron transfer behavior analysis, it is found that these active states play key role in the enhancement of photoactivity through narrowing the band-gap of TiO 2 , accelerating photoelectrons transfer from BE to TiO 2 , acting as electron traps and reaction sites for H 2 production.