Designing catalysts for water splitting based on electronic structure considerations

DOI: 10.1088/2516-1075/ab7d86

Authors: Sara Abdel Raze (Binghamton University) , Melissa Popeil (Binghamton University) , Linda W. Wangoh (Binghamton University) , Jatinkumar Rana (Binghamton University) , Nuwanthi Savindrika Suwandaratne (University at Buffalo - The State University of New York) , Justin Lee Andrews (Texas A&M University System) , David F. Watson (University at Buffalo - The State University of New York) , Sarbajit Banerjee (Texas A&M University System) , Louis Piper (Binghamton University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Electronic Structure

State: Published (Approved)
Published: March 2020
Diamond Proposal Number(s): 22148

Abstract: The disproportionation of H2O into solar fuels H2 and O2, or water splitting, is a promising strategy for clean energy harvesting and storage but requires the concerted action of absorption of photons, separation of excitons, charge diffusion to catalytic sites and catalysis of redox processes. It is increasingly evident that the rational design of photocatalysts for efficient water splitting must employ hybrid systems, where the different components perform light harvesting, charge separation and catalysis in tandem. In this Topical Review, we report on the recent development of a new class of hybrid photocatalysts that employs MxV2O5 (M= p-block cation) nanowires in order to engineer efficient charge transfer from the photoactive chalcogenide quantum dots (QDs) to the water-splitting and hydrogen evolving catalysts. Herein, we summarize the oxygen-mediated lone pair mechanism used to modulate the energy level and orbital character of mid-gap states in the MxV2O5 nanowires. The electronic structure of MxV2O5 is discussed in terms of density functional theory and hard x-ray photoelectron spectroscopy (HAXPES) measurements. The principles of HAXPES are explained within the context of its unique sensitivity to metal 5(6)s orbitals and ability to non-destructively study buried interface alignments of quantum dot decorated nanowires i.e., MxV2O5 /CdX (X= S, Se, Te). We illustrate with examples how the MxV2O5 /CdX band alignments can be rationally engineered for ultra-fast charge-transfer of photogenerated holes from the quantum dot to the nanowires; thereby suppressing anodic photo-corrosion in the CdX QDs and enabling efficacious hydrogen evolution.

Journal Keywords: Photocatalyst; Water Splitting; Electronic Structure; Band Alignment

Diamond Keywords: Photocatalysis

Subject Areas: Chemistry, Energy, Environment


Instruments: I09-Surface and Interface Structural Analysis

Added On: 09/04/2020 12:05

Documents:
Abdel+Raze+et+al_2020_Electron._Struct._10.1088_2516-1075_ab7d86.pdf

Discipline Tags:

Energy Storage Earth Sciences & Environment Sustainable Energy Systems Energy Climate Change Physical Chemistry Catalysis Chemistry

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS) Hard X-ray Photoelectron Spectroscopy (HAXPES)