Figure - available from: Discover Materials
This content is subject to copyright. Terms and conditions apply.
![Examples of PEC device structure classification (
adapted from Refs. [26] and [27]). Based on the classification scheme introduced in this study, device structures with SSJ-T are effectively considered as “wired” structures. Some of PEC device structures demonstrated by previous works are effectively “wired” structures, although the structure is seemingly “wireless”, because there are a three SSJ-T (Reprinted with permission from Ref. [26]. Copyright (2015) Elsevier), and b two SSJ-T and one SSJ-O (Reprinted with permission from Ref. [27]. Copyright (2015) American Chemical Society)](publication/360795538/figure/fig3/AS:1159091485442048@1653360353728/Examples-of-PEC-device-structure-classification-adapted-from-Refs-26-and-27.png)
Examples of PEC device structure classification ( adapted from Refs. [26] and [27]). Based on the classification scheme introduced in this study, device structures with SSJ-T are effectively considered as “wired” structures. Some of PEC device structures demonstrated by previous works are effectively “wired” structures, although the structure is seemingly “wireless”, because there are a three SSJ-T (Reprinted with permission from Ref. [26]. Copyright (2015) Elsevier), and b two SSJ-T and one SSJ-O (Reprinted with permission from Ref. [27]. Copyright (2015) American Chemical Society)
Source publication
![STH efficiencies from previous studies [7, 8, 11, 21, 26–74] as...](publication/360795538/figure/fig4/AS:1159091489644546@1653360354820/STH-efficiencies-from-previous-studies-7-8-11-21-26-74-as-function-of-the-number-of_Q320.jpg)
![STH efficiency from the previous studies [7, 8, 11, 21, 26–74]...](publication/360795538/figure/fig5/AS:1159091489652740@1653360354861/STH-efficiency-from-the-previous-studies-7-8-11-21-26-74-depending-on-the-pH-of-the_Q320.jpg)
A photoelectrochemical (PEC) water-splitting device integrates a photovoltaic cell and electrocatalysts into a single device to produce hydrogen fuel from water using solar irradiance. The major driving force behind PEC research is that it can potentially be a cost-efficient way to produce hydrogen in a renewable way, however, current PEC devices f...
Citations
... Advances in computational modeling and machine learning have enabled the rational design of catalysts with enhanced activity. By simulating the electronic structure and reaction kinetics, researchers can identify promising catalyst candidates for experimental validation, accelerating the discovery process [41][42][43]. ...
Water splitting, the process of converting water into hydrogen and oxygen gases, has garnered significant attention as a promising avenue for sustainable energy production. One area of focus has been the development of efficient and cost-effective catalysts for water splitting. Researchers have explored catalysts based on abundant and inexpensive materials such as nickel, iron, and cobalt, which have demonstrated improved performance and stability. These catalysts show promise for large-scale implementation and offer potential for reducing the reliance on expensive and scarce materials. Another avenue of research involves photoelectrochemical (PEC) cells, which utilize solar energy to drive the water-splitting reaction. Scientists have been working on designing novel materials, including metal oxides and semiconductors, to enhance light absorption and charge separation properties. These advancements in PEC technology aim to maximize the conversion of sunlight into chemical energy. Inspired by natural photosynthesis, artificial photosynthesis approaches have also gained traction. By integrating light-absorbing materials, catalysts, and membranes, these systems aim to mimic the complex processes of natural photosynthesis and produce hydrogen fuel from water. The development of efficient and stable artificial photosynthesis systems holds promise for sustainable and clean energy production. Tandem cells, which combine multiple light-absorbing materials with different bandgaps, have emerged as a strategy to enhance the efficiency of water-splitting systems. By capturing a broader range of the solar spectrum, tandem cells optimize light absorption and improve overall system performance. Lastly, advancements in electrocatalysis have played a critical role in water splitting. Researchers have focused on developing advanced electrocatalysts with high activity, selectivity, and stability for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). These electrocatalysts contribute to overall water-splitting efficiency and pave the way for practical implementation.
This comprehensive review delves into the intricacies of the photoelectrochemical (PEC) water splitting process, specifically focusing on the design, fabrication, and optimization of particle‐based photoelectrodes for efficient green hydrogen production. These photoelectrodes, composed of semiconductor materials, potentially harness light energy and generate charge carriers, driving water oxidation and reduction reactions. The versatility of particle‐based photoelectrodes as a platform for investigating and enhancing various semiconductor candidates is explored, particularly the emerging complex oxides with compelling charge transfer properties. However, the challenges presented by many factors influencing the performance and stability of these photoelectrodes, including particle size, shape, composition, morphology, surface modification, and electrode configuration, are highlighted. The review introduces the fundamental principles of semiconductor photoelectrodes for PEC water splitting, presents an exhaustive overview of different synthesis methods for semiconductor powders and their assembly into photoelectrodes, and discusses recent advances and challenges in photoelectrode material development. It concludes by offering promising strategies for improving photoelectrode performance and stability, such as the adoption of novel architectures and heterojunctions.
The demand for green-H 2 is steadily growing and PEC water splitting, one of the cleanest production routes, shall experience unparalleled economic and research stimulus, as the transition from lab-scale to commercial PEC devices is urgently needed.
The efficient conversion of solar energy into storable and distributable hydrogen is challenging, particularly in the development of cost-effective and efficient devices. As efficiency and cost are determined primarily by...
A photoelectrochemical (PEC) water splitting device based on a dual‐junction monolithic tandem cell that utilizes NiOOH/FeOOH/BiVO4/SnO2/Ta:SnO2 (TTO)/tunnel oxide passivated contact (TOPCon) Si is reported. The PEC device achieves a maximum photocurrent density of 1.4 mA cm⁻² (equal to a solar‐to‐hydrogen conversion efficiency of 1.72%) in 1.0 m potassium borate solution (pH 9) when illuminated with air mass 1.5 G simulated solar irradiation, which is the highest value among dual‐junction monolithic photoelectrochemical cells except for III–V materials. The TOPCon Si not only works as an appropriate bottom photoelectrode for subsequent high‐temperature BiVO4 processing but also offers a high photovoltage of 590 mV. Transparent and conductive TTO grown by pulsed laser deposition serves as a recombination layer to achieve effective integration. In addition, the TTO provides chemical and physical protection, allowing the surface of the TOPCon Si to exhibit 24 h of tandem cell stability under weak base electrolyte conditions. The SnO2 hole‐blocking layer inserted between TTO and BiVO4 enhances the charge separation of BiVO4, allowing the device to achieve high efficiency. Artificial leaf‐type monolithic tandem cells consisting of NiFe/BiVO4/SnO2/TTO/TOPCon Si/Ag/Ti/Pt with a solar‐to‐hydrogen efficiency of 0.44% are also demonstrated.
A new benign aqueous route toward bismuth‐containing photoelectrodes is proposed to eliminate the need for harmful organic solvents and/or acids. A CuBi2O4 photocathode is prepared by stabilizing the metal ions through complexation in pH neutral aqueous solutions. Merits of the proposed approach are elemental homogeneity (with unique doping possibilities) and ease of fabrication (e.g., high scalability). The prepared aqueous CuBi2O4 precursor forms a nearly phase‐pure kusachiite crystalline phase free of organics residuals and capable of water reduction due to its sufficiently negatively positioned conduction band at −0.4 V versus RHE. Deposition on fluorine doped tin oxide coated glass (FTO/glass) substrates and thermal treatment leads to uniform but granular films of CuBi2O4 with excellent control over stoichiometry and thickness, owing to the facile and non‐destructive synthesis conditions. Ultimately, the optimized CuBi2O4 photocathodes produce AM1.5G photocurrent densities of up to −1.02 mA cm⁻² at 0.4 V versus RHE with H2O2 as an electron scavenger, competing with bare CuBi2O4 prepared through less benign non‐aqueous organic synthesis routes.
Photoelectrochemical (PEC) water splitting is considered a promising technology to produce renewable hydrogen, a clean fuel or energy carrier to replace conventional carbon‐based fossil‐fuel sources. Nevertheless, the overall solar‐to‐hydrogen efficiency and the cost‐effectiveness of this technology are still unsatisfactory for practical implementation. This can be primarily attributed to the sluggish kinetics of the anodic oxygen evolution reaction (OER) and the relatively low economic value of cogenerated O2 production. Over the past decades, there are extensive efforts to explore more kinetically favorable photooxidation reactions, which coupled with hydrogen evolution reaction (HER) can simultaneously improve H2 production yield and produce higher valuable alternatives to conventional O2. This review aims to present recent progress on the alternative anodic choices to OER. Here, the fundamental of PEC water splitting and the critical components required for this system are first shortly summarized. Then the benefits and issues of alternative photooxidation reactions including photooxidation of water to hydrogen peroxide, chlorine, alcohol, 5‐hydroxymethylfurfural, or urea oxidation when combined with the concurrent HER, are reviewed and analyzed. This review is concluded by presenting a critical evaluation of the challenges and opportunities of these alternative HER‐coupled photooxidation reactions for solar energy production and environmental treatment.
