Structurally-New Hexadecanuclear Ni-Containing Silicotungstate with Catalytic Hydrogen Generation Activity

A structurally-new, carbon-free hexadecanuclear Ni-containing silicotungstate, [Ni-16(H2O)(15)(OH)(9)(PO4)(4)(SiW9O34)(3)](19-), has been facilely synthesized using a one-pot, solution-based synthetic method systematically characterized by single-crystal X-ray diffraction and several other techniques. The resulting complex works as a noble-metal-free catalyst for visible-light-driven catalytic generation of hydrogen, by coupling with a [Ir(coumarin)(2)(dtbbpy)][PF6] photosensitizer and a triethanolamine (TEOA) sacrificial electron donor. Under minimally optimized conditions, a turnover number (TON) of 842 was achieved for TBA-Ni16P4(SiW9)(3)-catalyzed hydrogen evolution system. The structural stability of TBA-Ni16P4(SiW9)(3) catalyst under photocatalytic conditions was evaluated by the mercury-poisoning test, FT-IR, and DLS measurements. The photocatalytic mechanism was elucidated by both time-solved luminescence decay and static emission quenching measurements.

Automated summary

A new structurally-new carbon-free hexadecanuclear Ni-containing silicotungstate compound was synthesized and characterized using single-crystal X-ray diffraction and other techniques. The compound serves as a noble-metal-free catalyst for visible-light-driven catalytic hydrogen generation by coupling with a photosensitizer and sacrificial electron donor. Under optimized conditions, a turnover number of 842 was achieved for the TBA-Ni16P4(SiW9)(3)-catalyzed hydrogen evolution system. The structural stability of the catalyst under photocatalytic conditions was evaluated using mercury-poisoning test, FT-IR, and DLS measurements. The photocatalytic mechanism was elucidated through luminescence decay and emission quenching measurements.