Related Experiment Video
Updated: Aug 5, 2026
05:41
Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods
Published on: February 11, 2016
Interfacial Regulation by a NiO x Overlayer Enables Enhanced Near-Infrared Photoelectrochemical Water Splitting
Xiao-Feng Shen1,2, Kyle J Stephens2,3, Dengyao Yang1
1International Institute for Carbon-Neutral Energy Research Kyushu University Fukuoka Japan.
Small Science
|July 29, 2026
Summary
This study introduces a novel near-infrared (NIR) responsive dye-sensitized photoanode for efficient solar fuel production. The addition of a nickel oxide (NiO_x) overlayer significantly boosts photocurrent and extends photoelectrochemical activity into the NIR region.
Area of Science:
- Materials Science
- Electrochemistry
- Renewable Energy
Background:
- Photoelectrochemical (PEC) water splitting is key for sustainable hydrogen production.
- Inefficient utilization of near-infrared (NIR) light limits solar energy conversion efficiency in PEC systems.
Purpose of the Study:
- To develop a NIR-responsive dye-sensitized photoanode for enhanced solar fuel conversion.
- To investigate the role of a nickel oxide (NiO_x) overlayer in improving PEC performance.
Main Methods:
- Fabrication of a dye-sensitized photoanode using a boron-dipyrromethene-carbazole sensitizer.
- Deposition of a NiO_x overlayer via low-temperature pulsed laser deposition.
- Characterization using transmission electron microscopy and X-ray photoelectron spectroscopy.
- Electrochemical testing to evaluate photocurrent density, photostability, and spectral response.
Main Results:
- The NiO_x overlayer increased photocurrent density by 1.9-fold and improved photostability.
- The modified photoanode demonstrated sustained photocurrent response up to 850 nm, extending activity into the NIR region.
- NiO_x acted as both an oxygen evolution reaction (OER) cocatalyst and an interface regulator, enhancing charge transfer and reaction efficiency.
Conclusions:
- The developed NiO_x-modified photoanode offers a viable strategy for NIR-driven solar fuel conversion.
- Synergistic functions of NiO_x in interfacial charge regulation and catalytic kinetics are crucial for improved performance.
- This work establishes a new benchmark for long-wavelength photoelectrocatalytic performance in non-noble-metal dye-sensitized systems.
Related Concept Videos
01:34The Z-Scheme of Electron Transport in Photosynthesis
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
01:27Photosystem I
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
01:11P-N junction
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
01:06Interfacial Electrochemical Methods: Overview
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current passing...
01:29The Photochemical Reaction Center
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
01:22Photosystem II
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...