First Principle Modelling of Materials and Processes in Dye-Sensitized Photoanodes for Solar Energy and Solar Fuels

Abstract

Abstract:In the context of solar energy exploitation, dye-sensitized solar cells and dye-sensitized photoelectrosynthetic cells offer the promise of low-cost sunlight conversion and storage, respectively. In this perspective we discuss the main successes and limitations of modern computational methodologies, ranging from hybrid and long-range corrected density functionals, GW approaches and multi-reference perturbation theories, in describing the electronic and optical properties of isolated components and complex interfaces relevant to these devices. While computational modelling has had a crucial role in the development of the dye-sensitized solar cells technology, the theoretical characterization of the interface structure and interfacial processes in water splitting devices is still at its infancy, especially concerning the electron and hole transfer phenomena. Quantitative analysis of interfacial charge separation and recombination reactions in multiple metal-oxide/dye/catalyst heterointerfaces, thus, undoubtedly represents the compelling challenge in the field of modern computational material science.

Recent advances in computational photocatalysis: A review

“…Comparatively, for Fe‐doped TiO 2 , Fe 3d states were located between the band gap of TiO 2 , which decrease the band gap and increase the absorption of visible light photons. Recently, the optical spectra can be also simulated via the time‐dependent DFT (TDDFT) and Green's function methods (e.g., the GW approximation (GWA) and Bethe‐Salpeter equation), which were found to be more accurate . Despite these differences between the simulated and experimental results, simulation is an effective approach to study optical absorption intensity, especially for a new material design …”

Electronic structure and optical properties of isolated and TiO2‐grafted free base porphyrins for water oxidation: A challenging test case for DFT and TD‐DFT

“…At the base of the efficient dye‐sensitized photoelectrodes, there is the optimal integration of the three main components: the dye sensitizer, the semiconductor, and the catalyst . While the development of molecular components (catalysts and sensitizers) for the proton reduction, half reaction has reached important advances over the last years and the main limiting factor on the photocathode side is represented by the nonoptimal characteristics of the p ‐type semiconductor (NiO), the four‐electron water oxidation reaction, requiring the accumulation of four oxidative equivalents at a catalyst site in competition with back electron transfer of injected electrons to the oxidized dye‐catalyst assembly, is the main bottleneck toward the design of efficient and stable water splitting devices.…”

“…[11][12][13] At the base of the efficient dye-sensitized photoelectrodes, there is the optimal integration of the three main components: the dye sensitizer, the semiconductor, and the catalyst. [14][15][16][17] While the development of molecular components (catalysts and sensitizers) for the proton reduction, half reaction has reached important advances over the last years [18][19][20][21] and the main limiting factor on the photocathode side is represented by the nonoptimal characteristics of the p-type semiconductor (NiO), [13,[22][23][24] the four-electron water oxidation reaction, requiring the accumulation of four oxidative equivalents at a catalyst site in competition with back electron transfer of injected electrons to the oxidized dye-catalyst assembly, [4,9,[25][26][27][28] is the main bottleneck toward the design of efficient and stable water splitting devices. To assure effective light harvesting and interfacial charge (electron/hole) separation, the dye sensitizer should possess a wide and intense optical absorption spectrum, extending to the red and near infra-red regions, a long-lived charge-separated excited state, possibly strongly electronically coupled to the oxide CB states, and ground and excited state oxidation potentials (ESOPs), which properly match the redox potential of the catalyst and the semiconductor CB/VB, Figure 1.…”

23-Electron Octahedral Molybdenum Cluster Complex [{Mo6I8}Cl6]−

“…Systems that demonstrate reversible redox properties combined with photoluminescence properties are highly interesting for applications based on electron transfer or photoinduced electron transfer, such as photovoltaics, 1 photo/electrocatalysis 2,3 and light-emitting diodes (LEDs). [4][5][6] In these regards transition metal complexes are in the focus of the global research community, due to the rich diversity of their electrochemical and optical properties.…”

“…[4][5][6] In these regards transition metal complexes are in the focus of the global research community, due to the rich diversity of their electrochemical and optical properties. The most famous exemplars of such systems are based on precious metals such as Ru(II) complexes for dyesensitized solar cells, 1 Re(I) carbonyl complexes for photo-/electro-catalytic reduction of CO2 2,3 and photoluminescent Ir(III) complexes as photoemissive elements of organic LEDs. [4][5][6] Photoluminescent octahedral cluster complexes of molybdenum, tungsten and rhenium, are apical organic or inorganic ligands), respectively, have recently emerged as a new photoactive elements in photovoltaic 7,8 , photocatalytic [9][10][11][12][13][14] and lighting applications.…”