Abstract
Sustainable solutions for hydrogen production, such as dye-sensitized photoelectrochemical cells (DS-PEC), rely on the fundamental properties of its components whose modularity allows for their separate investigation. In this work, we design and execute a high-throughput scheme to tune the ground state oxidation potential (GSOP) of perylene-type dyes by functionalizing them with different ligands. This allows us to identify promising candidates which can then be used to improve the cell's efficiency. First, we investigate the accuracy of different theoretical approaches by benchmarking them against experimentally determined GSOPs. We test different methods to calculate the vertical oxidation potential, including GW with different levels of self-consistency, Kohn–Sham (KS) orbital energies and total energy differences. We find that there is little difference in the performance of these methods. However, we show that it is crucial to take into account solvent effects as well as the structural relaxation of the dye after oxidation. Other thermodynamic contributions are negligible. Based on this benchmark, we decide on an optimal strategy, balancing computational cost and accuracy, to screen more than 1000 dyes and identify promising candidates which could be used to construct more robust DS-PECs.
Highlights
Hydrogen is seen as a symbol of sustainable energy source, even though its production currently mostly relies on fossil fuels.[1,2] To make production of this energy carrier more sustainable,[3,4,5] a promising route is to split water with a dyesensitized photoelectrochemical cell (DS-PEC) driven by solar energy.[6,7] Such developments capitalize on the advantages of dye-sensitization, in particular the possibility to tune the dye’s properties by small structural adjustments.[7]A further boundary condition for sustainable deployment of dye-sensitized photoelectrochemical cells (DS-PEC) is the use of dyes made entirely from abundant material, such as fully organic dyes
We considered different variants of non self-consistent GW (G0W0) and partially self-consistent GW: G0W0@PBE0(HF = 0.4) (G0W0 performed on top of a PBE095,96 calculations with 40% exact exchange), G0W0@LRCoPBEH,[97] eigenvalue-only self-consistent GW based on the same two functionals (evGW@PBE0(HF = 0.4) and eigenvalueonly self-consistent GW (evGW)@LRC-oPBEH), QP self-consistent GW as well as QP self-consistent GW with self-consistency only in G, but not in W based on a PBE starting point
First we have built the experimental data set from the cyclic voltammetry (CV) measurements for the derivatives of the naphtalene diimide (NDI) and perylene diimides (PDI) dyes to validate the computational results
Summary
Hydrogen is seen as a symbol of sustainable energy source, even though its production currently mostly relies on fossil fuels.[1,2] To make production of this energy carrier more sustainable,[3,4,5] a promising route is to split water with a dyesensitized photoelectrochemical cell (DS-PEC) driven by solar energy.[6,7] Such developments capitalize on the advantages of dye-sensitization, in particular the possibility to tune the dye’s properties by small structural adjustments.[7]A further boundary condition for sustainable deployment of DS-PECs is the use of dyes made entirely from abundant material, such as fully organic dyes. Perylene diimides (PDI) have been recognised as very promising for use in photovoltaic devices[7,9] due to their favourable optical and electrochemical properties, as well as their stability, relatively cheap synthesis and tunability. They have found a place in different types of photo-electrochemical devices, both at the anode[10,11,12,13] and at the cathode.[14] other dyes related to the perylene diimide have proven to be efficient components of such systems, like naphtalene diimide (NDI)[15] or perylene triimides (PTI).[16]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
