The ionization potential of aqueous hydroxide computed using many-body perturbation theory

Opalka, Daniel; Pham, Tuan Anh; Sprik, Michiel; Galli, Giulia

doi:10.1063/1.4887259

Cited by 35 publications

(53 citation statements)

References 26 publications

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“…Many-body perturbation theory based on Hedin's GW approximation [11], is a more rigorous approach to the problem of electronic excitations. As the GW method is computationally demanding, one-shot or partial self-consistent calculations are usually performed for aqueous solutions [12][13][14][15][16][17][18]. However, these calculations are tied to the specific choice of the starting point, and band gaps varying between 7.3 to 9.5 eV have been reported for liquid water [12][13][14][15]17].…”

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confidence: 99%

Ab initio Electronic Structure of Liquid Water

et al. 2016

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Self-consistent GW calculations with efficient vertex corrections are employed to determine the electronic structure of liquid water. Nuclear quantum effects are taken into account through ab initio pathintegral molecular dynamics simulations. We reveal a sizable band-gap renormalization of up to 0.7 eV due to hydrogen-bond quantum fluctuations. Our calculations lead to a band gap of 8.9 eV, in accord with the experimental estimate. We further resolve the ambiguities in the band-edge positions of liquid water. The valence-band maximum and the conduction-band minimum are found at −9.4 and −0.5 eV with respect to the vacuum level, respectively. DOI: 10.1103/PhysRevLett.117.186401 Liquid water is such a ubiquitous substance that it has been the subject of upsurging research efforts for the past 30 years. Of particular importance is the electronic structure of liquid water, the significance of which has been recently highlighted in clean-energy technologies through semiconductor-assisted artificial photosynthesis [1,2]. A good understanding of the electronic structure of water is a prerequisite toward the design of photocatalytic systems with high catalytic activity.The extended hydrogen-bond network of liquid water gives rise to the formation of electronic bands. The valence band maximum (VBM) is characterized by the localized 2p z electrons of O atoms. The conduction band minimum (CBM) derives from the antibonding orbitals of O-H bonds, and is at variance much more extended. Experimentally determined positions of these band edge states have yet to reach a consensus. Early ultraviolet (UV) photoemission experiments by Delahay and collaborators reported photoemission threshold energies of 9.3 [3] and 10.06 eV [4]. More recent work by Winter et al. employed the liquid microjet technique and found a threshold energy of 9.9 eV [5]. For the unoccupied states, inverse photoemission and photoionization measurements placed the CBM at −1.2 eV with respect to the vacuum level [6,7]. This value was later revised to −0.74 eV, in light of the observation that excess electrons in liquid water could be initially captured in a localized trap state below the actual CBM [8]. Altogether, these measurements allude to a band gap of 8.7 eV, but associated with a sizable uncertainty of AE0.6 eV.To shed light on the electronic structure of water, it is necessary to resort to a fully ab initio method, which avoids the use of experimental input. Ab initio molecular dynamics (MD) simulations based on Kohn-Sham density-functional theory (DFT) have been extensively carried out to understand the structural and dynamical properties of water and of aqueous solutions. It is well recognized that the use of semilocal density functionals precludes a faithful description of the electronic structure and the predicted band gap of liquid water is apparently too small [9,10]. Hybrid functionals improve the description of the electronic structure [10], but the mixing parameter of the Fock exchange is not known a priori without the input from experiment ...

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confidence: 99%

Ab initio Electronic Structure of Liquid Water

et al. 2016

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“…44,72 Finite temperature fluctuations, neglected in our calculations, may also help bring the ÀEA below the redox potential of the dopant molecules. 73 The preceding discussion shows that several physical mechanisms are available to fill the IGS of CdSe NPs, thereby activating the IB-mediated absorption processes.…”

Section: Articlementioning

confidence: 98%

Colloidal Nanoparticles for Intermediate Band Solar Cells

2015

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The Intermediate Band (IB) solar cell concept is a promising idea to transcend the Shockley-Queisser limit. Using the results of first-principles calculations, we propose that colloidal nanoparticles (CNPs) are a viable and efficient platform for the implementation of the IB solar cell concept. We focused on CdSe CNPs and we showed that intragap states present in the isolated CNPs with reconstructed surfaces combine to form an IB in arrays of CNPs, which is well separated from the valence and conduction band edges. We demonstrated that optical transitions to and from the IB are active. We also showed that the IB can be electron doped in a solution, e.g., by decamethylcobaltocene, thus activating an IB-induced absorption process. Our results, together with the recent report of a nearly 10% efficient CNP solar cell, indicate that colloidal nanoparticle intermediate band solar cells are a promising platform to overcome the Shockley-Queisser limit.

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“…262 Historically, these techniques have been considered too expensive for application to PEC interfaces; however, recent algorithmic developments [263][264][265] allows one to apply the GW method to larger system sizes, permitting direct treatment of both the solid electrode and liquid electrolyte. [266][267][268][269][270] This opens up opportunities to investigate how local electronic states are altered by the presence of the liquid electrolyte within a formalism that is often more robust than TDDFT, and provides a possible template for comparison with high-resolution experimental probes. As alternatives to the GW/BSE approach, high-level quantum chemistry methods such as Møller-Plesset perturbation theory (MPn), 271 coupled cluster theory (CC), 272 configuration interaction (CI), 273 complete active space self-consistent field (CASSCF), 274 and complete active space with second-order perturbation theory (CASPT2) 275 can be employed to calculate excited-state properties.…”

Section: Excited-state and Beyond-dft Methodsmentioning

confidence: 99%