Photocatalytic H2 generation based on noble-metal-free Co(II) photocatalyst under visible-light-driven

Abstract

Keywords:Cobalt(II) photocatalyst Photocatalytic system based solely upon noble-metal-free system Photocatalysis H 2 generation Mechanism a b s t r a c t A noble-metal-free catalyst, namely Co(II) complex [Co(dbp) 2 ]Cl 2 (dbp ¼ 4,4 0 -dimethyl-2,2 0 -bipyridyl), had been prepared for photocatalytic H 2 generation. The H 2 generation was achieved by the constructed homogeneous photocatalytic system comprising of [Co(dbp) 2 ]Cl 2 as catalyst, Eosin Y as photosensitizer and triethanolamine as sacrifice agent under visible-light-driven (l > 420 nm). The maximum H 2 yield of 169.2 mmol appeared at target catalyst of 4.0 Â 10 À4 M, EY 2À of 4.0 Â 10 À4 M and 10% TEOA (v/v) at pH 9 in CH 3 CN/H 2 O of 1:1 (v/v), indicating that this complex could also be used as a potential photocatalytic material for H 2 evolution under the irradiation of visible light. In addition, the H 2 generation mechanism was also briefly discussed.

Unlocking the potential of ketocoumarins: efficient photosensitizers for sustainable light driven hydrogen evolution

“…An additional challenge in the production of Ru/Pt/Ir metal complex photosensitizers on a large scale is the scarcity and cost of the rare earth metals used in their synthesis. Only a few examples can be found in literature, where metal-free photosensitizers like BODIPY [16][17][18] or xanthene-based dyes [19][20][21][22][23][24][25][26] are used in conjunction with cobaloxime or other cobalt complexes. In all of these cases, heavy halogen atoms were used to facilitate efficient singlet-triplet crossing of the dye.…”