Homogeneous catalyses of mixed-valent octanuclear platinum complexes in photochemical hydrogen production from water

Spectroelectrochemical evidence of the role of viologen moiety as an electron transfer mediator from ITO substrate to a Pt complex acting as a confined molecular catalyst for hydrogen evolution reaction

“…This result clearly shows that the confinement of the Pt complex accelerates HER significantly as observed before at Si(111) electrode [11]. No significant changes in the absorbance at 400 and 600 nm were observed within this potential range ( Figures 1 (b) and (c)) and no peaks were observed in the UV/vis spectra at all potentials as 7 shown in Figure 2(b), suggesting that the viologen moiety in the monolayer in steady state is V 2+ at all potentials. This suggests that as soon as V +• or V 0 is formed, electron is transferred to the Pt complex, which in turn transfers electron to H + to generate hydrogen as we suggested before [11].…”

“…Because of high cost and limited resources, many efforts have been made to develop non-precious metal catalyst and maximize the utilization of these elements. Although molecular and single atom catalysts are expected to have 100% atom efficiency [4][5][6][7][8], both have difficulties in practical use. Molecular catalysts are usually used as homogeneous catalyst in solution and are difficult to be separated from reactants and products after the reaction.…”

Tris(2,2′‐bipyridine)ruthenium Derivatives with Multiple Viologen Acceptors: Quadratic Dependence of Photocatalytic H2 Evolution Rate on the Local Concentration of the Acceptor Site

“…PVP‐protected colloidal Pt (2 nm in particle size) was purchased from Tanaka Holdings Co., Ltd. All other chemicals and solvents were purchased from Kanto Chemicals Co., Inc. and used without further purification. 4,4′‐MV2(PF 6 ) 4 ⋅ 2 H 2 O, 4,4′‐MV4(PF 6 ) 8 ⋅ 5 H 2 O, [Ru(bpy) 2 (5,5′‐MV4)](PF 6 ) 10 ⋅ H 2 O, [Ru(4,4′‐MV4) 3 ](PF 6 ) 26 ⋅ 12 H 2 O, 4,4′‐bis( N ‐methylcarbamoyl)‐2,2′‐bipyridine (4,4′‐ME2), cis ‐Ru(bpy) 2 Cl 2 , H[Ru(bpy)Cl 4 ], [Ru(4,4′‐ME2) 3 ](PF 6 ) 2 ⋅ 2 H 2 O, [Ru(bpy) 3 ](NO 3 ) 2 ⋅ 3 H 2 O, and MV(NO 3 ) 2 were synthesized as previously described.…”

Photocatalytic H2 Evolution Using a Ru Chromophore Tethered to Six Viologen Acceptors

“…PVP‐protected colloidal Pt (2 nm in particle size) was purchased from Tanaka Holdings Co., Ltd. All other chemicals and solvents were purchased from Kanto Chemicals Co., Inc. and used without further purification. [bpyMV2](PF 6 ) 4 ⋅ 2 H 2 O, cis ‐[RuCl 2 (DMSO) 4 ], [Ru(bpy) 3 ](NO 3 ) 2 ⋅ 3 H 2 O, and MV(NO 3 ) 2 were synthesized as previously described.…”