Will Solar-Driven Water-Splitting Devices See the Light of Day?

Abstract

Through decades of sustained effort, researchers have made substantial progress on developing technologies for solar-driven water splitting. Nevertheless, more basic research is needed before prototype devices with a chance for commercial success can be demonstrated. In this Perspective, we summarize the major design constraints that motivate continued research in the field of solar-driven water splitting. Additionally, we discuss key device components that are now available for use in demonstration systems and prototypes. Finally, we highlight research areas where breakthroughs will be critical for continued progress toward commercial viability for solar-driven water-splitting devices.

Tracking the Structural and Electronic Configurations of a Cobalt Proton Reduction Catalyst in Water

“…2 were too small for XAS collection and XAS analysis. Ultrapure (Type 1) water (resistivity 18.2 MΩ.cm at 25°C, TOC 4 µg/L) sourced from a Q-POD unit of Milli-Q integral water purification system (Millipore) was used to prepare the catalytic solutions.…”

“…STOs are better from a theoretical point of view since they have the correct behavior near the nucleus and the correct asymptotic long-range behavior. Typically, fewer STOs than gaussian GTOs are needed to reach a certain level of accuracy, as discussed in Güell et al 68 The X-ray absorption cross section obeys the Fermi golden rule, and the matrix element for the electron transition can be written as (2) where ψ 1s is a core−electron wave function, ψ f is a wave function for the unoccupied state, ε is a photon polarization, k is a photon wavevector. Both dipole and quadrupole terms were taken into account: The averaging was performed for all directions of photon polarization and wave vector with a restriction of perpendicularity of these two vectors.…”

“…The manuscript is divided according to the sequential processes taking place in the reaction, as illustrated in Scheme 2. Thus, we start by reporting experimental and theoretical XAS simulations of the bis(chloro) [ 2 ] 3+ complexes shown in Scheme 1, both in solid and solution form, were studied by X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy (Fig. 1).…”

Sol–gel copper chromium delafossite thin films as stable oxide photocathodes for water splitting

“…Water splitting seems to be one of the most convenient ways to reach this goal. [1][2][3] Hydrogen could play a very important role due to its potential use in clean energy applications. 4 As a consequence, achieving high efficiency in solar water photosplitting would contribute to convert our fossil fuel dependent society into another one whose development would be based on renewable energy.…”

Methods of photoelectrode characterization with high spatial and temporal resolution

“…[1][2][3][4] However, no PEC system has been demonstrated to date that can meet the efficiency, stability, and cost targets 5 needed for an economically viable PEC technology. 6 One of the major barriers to commercialization is the lack of suitable materials to be used in photoelectrodes, 2,4 the ''engines'' a Department of Chemical Engineering, Columbia University in the City of New York, of PEC devices that are responsible for absorbing light and using the resulting potential energy difference to drive the water splitting reaction. To perform these functions with high efficiency and durability, photoelectrode materials and architectures are needed that are extremely stable, absorb a significant portion of the solar spectrum, possess high catalytic activity for the hydrogen-and oxygen-evolution reactions (HER and OER, respectively), produce a large photovoltage, exhibit high carrier lifetimes, and are predominantly comprised of earth-abundant elements.…”