Modulating Surface/Interface Structure of Emerging InGaN Nanowires for Efficient Photoelectrochemical Water Splitting

Abstract

Photoelectrochemical (PEC) water splitting provides a promising approach to convert solar energy into hydrogen. Developing active, stable, and cost-effective semiconductors photoelectrodes is of great significance for achieving high-efficiency and large-scale hydrogen production. InGaN nanowires as an important candidate have gained a great upsurge in solar water splitting due to its tunable gap, high electron mobility, large active area, and excellent chemical stability. To obtain state-of-the-art InGaN nanowires-based photoelectrodes, tremendous efforts have been devoted to enhance light absorption capacity, charge carrier dynamics, and redox activity. In this review, recent advances in InGaN nanowires as photoelectrodes for PEC water splitting are comprehensively presented, with a focus on photoelectrode optimization strategies from the aspects of surface and interface structure modulation including doping engineering, energy band engineering, heterostructure engineering, and micro-nano engineering. The representative applications of InGaN nanowires-based PEC tandem cell are also discussed. Finally, perspectives on remaining challenges and future development are outlined.

Photovoltage‐Competing Dynamics in Photoelectrochemical Devices: Achieving Self‐Powered Spectrally Distinctive Photodetection

“…This process is known as oxygen evolution reaction (OER). [23,27] Thereafter, a complete current loop is formed and the positive photocurrent can be obtained, which can be monitored by the electrochemical workstation. In contrast, when the device is exposed to Light-II (Figure 1b), only SC-II can absorb photons.…”

“…When the cell is illuminated, as schematically shown in Figure 1, the photoelectrode absorbs photons to excite electrons (e − ) from its valence band (VB) to the conduction band (CB) and leaves holes (h + ) in the VB. [26,27] In this case, the quasi-Fermi level of electrons (E F, n ) and holes (E F, p ) are used to describe the interfacial thermodynamics. And the corresponding photovoltage (V ph ) of the photoelectrode is defined as the value difference between the quasi-Fermi level of electrons and holes under illumination.…”

“…These electrons undergo reduction reactions (4e − + 4H + → 2H 2 ), which is called hydrogen evolution reaction (HER). [23,27] Moreover, the upward surface band bending of SC-I acts as the driving force which pushes the photoexcited holes in SC-I readily migrating to the SC-I/electrolyte interface and participating in oxidation reactions (4h…”

Bayesian Optimization of Hubbard U’s for Investigating InGaN Superlattices

“…Hence, we are confident that LDA+U with the optimized Us is an attractive approach offering performance similar to that of HSE06 at a tiny fraction of its cost when computing band gaps and E-fields of InGaN superlattices, e.g., in digital alloys [15]. This performance gain might prove helpful when studying, engineering, and optimizing the electronic properties of InGaN nanostructures for light-emitting diodes [52][53][54], gas sensing [55], electrochemical devices [56], solar energy harvesting, and conversion [57][58][59][60], such as InGaN nanowires, core-shell structures, and quantum dots.…”

Enhancement of Interfacial Charge Transportation Through Construction of 2D–2D p–n Heterojunctions in Hierarchical 3D CNFs/MoS2/ZnIn2S4 Composites to Enable High‐Efficiency Photocatalytic Hydrogen Evolution

“…To date, extensive striving have been committed to broaden visible‐light responsive photocatalysts for high‐efficiency H 2 production. [ 1–4 ] Among the various catalysts, such as transition metal nitrides, [ 5–7 ] the 2D ternary chalcogenide ZnIn 2 S 4 is a highly promising n‐type semiconductor for photocatalytic H 2 evolution, [ 8–10 ] thanks to its good visible‐light‐harvesting capability (energy bandgap [ E g ] = 2.34–2.48 eV), photostability, and nontoxicity. [ 11,12 ] Yet the single‐phase ZnIn 2 S 4 catalyst typically suffers from serious deterioration in both photocatalytic activity over H 2 evolution, due to its physical and structural deficiencies.…”