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

• A homogeneous photocatalytic system based solely upon noble-metal-free was reported.
• Max H2 yield for [Co(dbp)2]Cl2 complex was 169.2 μmol (vs.Cat.) in optimal condition.
• Sacrifice agent, pH value and ratio of CH3CN to H2O critically affected H2 evolution.
• Inactivity of system was mainly due to photodegradation from EY2− and catalyst.
• Target complex could be used as a potential catalyst for photocatalytic H2 evolution.

A noble-metal-free catalyst, namely Co(II) complex [Co(dbp)2]Cl2 (dbp = 4,4′-dimethyl-2,2′-bipyridyl), had been prepared for photocatalytic H2 generation. The H2 generation was achieved by the constructed homogeneous photocatalytic system comprising of [Co(dbp)2]Cl2 as catalyst, Eosin Y as photosensitizer and triethanolamine as sacrifice agent under visible-light-driven (λ > 420 nm). The maximum H2 yield of 169.2 μmol appeared at target catalyst of 4.0 × 10−4 M, EY2− of 4.0 × 10−4 M and 10% TEOA (v/v) at pH 9 in CH3CN/H2O of 1:1 (v/v), indicating that this complex could also be used as a potential photocatalytic material for H2 evolution under the irradiation of visible light. In addition, the H2 generation mechanism was also briefly discussed.