Organic Dye-Sensitized Tandem Photoelectrochemical Cell for Light Driven Total Water Splitting

Abstract

Light driven water splitting was achieved by a tandem dye-sensitized photoelectrochemical cell with two photoactive electrodes. The photoanode is constituted by an organic dye L0 as photosensitizer and a molecular complex Ru1 as water oxidation catalyst on meso-porous TiO2, while the photocathode is constructed with an organic dye P1 as photoabsorber and a molecular complex Co1 as hydrogen generation catalyst on nanostructured NiO. By combining the photocathode and the photoanode, this tandem DS-PEC cell can split water by visible light under neutral pH conditions without applying any bias.

Solar H2 evolution in water with modified diketopyrrolopyrrole dyes immobilised on molecular Co and Ni catalyst–TiO2 hybrids

“…Light-driven H 2 evolution with organic dyes in combination with a metal oxide semiconductor has been previously reported, but these systems required either a Pt co-catalyst, a p-type semiconductor electrode, organic solvents or an anchor-free diffusional dye. 8,27–30 Only few studies are available with organic chromophores under DSP conditions and even less with commonly used aqueous electron donors, such as triethanolamine (TEOA) or ascorbic acid (AA), or with a molecular catalyst in a semi-heterogeneous photocatalytic scheme. 11,31–34 …”

An aqueous, organic dye derivatized SnO2/TiO2 core/shell photoanode

“…[7][8][9] In these applications, Ru(II) polypyridyl complex derivatives of Ru II (bpy) 3 2+ (bpy is 2,2`bipyridine) have provided an ubiquitous class of photosensitizers for photoanode applications and water oxidation due to their favorable properties including stability in water and tunable light absorption and redox potentials. 10,11 Examples of organic chromophores capable of driving water oxidation at DSPEC photoanodes are limited [12][13][14][15][16] even given the large portfolio of organic dyes developed for dye-sensitized solar cells (DSSCs). 16 In using these dyes, significant challenges arise from combining broad light absorption, efficient excited state injection, catalyst oxidation, and aqueous solution stability.…”

A Noble‐Metal‐Free Heterogeneous Photosensitizer‐Relay Catalyst Triad That Catalyzes Water Oxidation under Visible Light

“…[2,3] Of these,d ye-sensitized photoelectrochemical cells (DS-PECs) utilize covalently coordinated chromophore-water oxidation catalyst (WOC) dyad assemblies [4][5][6] in an effort to mimic natural photosynthesis. [10][11][12][13][14][15][16][17][18][19] Although the use of robust heterogeneous assemblies such as oxides could be apromising solution to improve stability,the lack of complete control on the coordination of metal ions in oxide chemistry does not allow the preparation of oxidebased dyads. [7][8][9] Molecular ruthenium complexes (as photosensitizers and/or WOCs) remain the most widely used despite their high cost and easy decomposition under photocatalytic conditions.…”