scholarly journals Metal Chalcogenides on Silicon Photocathodes for Efficient Water Splitting: A Mini Overview

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 149 ◽  
Author(s):  
Jemee Joe ◽  
Hyunwoo Yang ◽  
Changdeuck Bae ◽  
Hyunjung Shin
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Active Sites ◽  
Transition Metal Dichalcogenides ◽  
Atomic Layer ◽  
Future Research ◽  
Metal Chalcogenides ◽  
Surface Band ◽  
Band Bending ◽  
Co Catalysts

In the photoelectrochemical (PEC) water splitting (WS) reactions, a photon is absorbed by a semiconductor, generating electron-hole pairs which are transferred across the semiconductor/electrolyte interface to reduce or oxidize water into oxygen or hydrogen. Catalytic junctions are commonly combined with semiconductor absorbers, providing electrochemically active sites for charge transfer across the interface and increasing the surface band bending to improve the PEC performance. In this review, we focus on transition metal (di)chalcogenide [TM(D)C] catalysts in conjunction with silicon photoelectrode as Earth-abundant materials systems. Surprisingly, there is a limited number of reports in Si/TM(D)C for PEC WS in the literature. We provide almost a complete survey on both layered TMDC and non-layered transition metal dichalcogenides (TMC) co-catalysts on Si photoelectrodes, mainly photocathodes. The mechanisms of the photovoltaic power conversion of silicon devices are summarized with emphasis on the exact role of catalysts. Diverse approaches to the improved PEC performance and the proposed synergetic functions of catalysts on the underlying Si are reviewed. Atomic layer deposition of TM(D)C materials as a new methodology for directly growing them and its implication for low-temperature growth on defect chemistry are featured. The multi-phase TM(D)C overlayers on Si and the operation principles are highlighted. Finally, challenges and directions regarding future research for achieving the theoretical PEC performance of Si-based photoelectrodes are provided.

scholarly journals Nanocarbon-Enhanced 2D Photoelectrodes: A New Paradigm in Photoelectrochemical Water Splitting

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jun Ke ◽  
Fan He ◽  
Hui Wu ◽  
Siliu Lyu ◽  
Jie Liu ◽  
...  
Keyword(s):  
Solar Energy ◽  
Water Splitting ◽  
Transition Metal Dichalcogenides ◽  
Future Research ◽  
New Paradigm ◽  
Co Catalysts ◽  
Challenges And Opportunities ◽  
Metal Dichalcogenides ◽  
Double Hydroxides ◽  
Pec Water Splitting

AbstractSolar-driven photoelectrochemical (PEC) water splitting systems are highly promising for converting solar energy into clean and sustainable chemical energy. In such PEC systems, an integrated photoelectrode incorporates a light harvester for absorbing solar energy, an interlayer for transporting photogenerated charge carriers, and a co-catalyst for triggering redox reactions. Thus, understanding the correlations between the intrinsic structural properties and functions of the photoelectrodes is crucial. Here we critically examine various 2D layered photoanodes/photocathodes, including graphitic carbon nitrides, transition metal dichalcogenides, layered double hydroxides, layered bismuth oxyhalide nanosheets, and MXenes, combined with advanced nanocarbons (carbon dots, carbon nanotubes, graphene, and graphdiyne) as co-catalysts to assemble integrated photoelectrodes for oxygen evolution/hydrogen evolution reactions. The fundamental principles of PEC water splitting and physicochemical properties of photoelectrodes and the associated catalytic reactions are analyzed. Elaborate strategies for the assembly of 2D photoelectrodes with nanocarbons to enhance the PEC performances are introduced. The mechanisms of interplay of 2D photoelectrodes and nanocarbon co-catalysts are further discussed. The challenges and opportunities in the field are identified to guide future research for maximizing the conversion efficiency of PEC water splitting.

Layered Ternary and Quaternary Transition Metal Chalcogenide Based Catalysts for Water Splitting

2018 ◽  
Author(s):  
Anand P. Tiwari ◽  
Travis G. Novak ◽  
Xiuming Bu ◽  
Johnny C. Ho ◽  
Seokwoo Jeon
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Surface Engineering ◽  
Precious Metals ◽  
Future Research ◽  
Metal Chalcogenides ◽  
Comprehensive Overview ◽  
Energy Devices ◽  
Recent Developments ◽  
Electrochemical Water Splitting

Water splitting plays an important role in electrochemical and photoelectrochemical conversion of energy devices. Electrochemical water splitting by the hydrogen evolution reaction (HER) is a straightforward route to produce hydrogen (H2), which requires an efficient electrocatalysts to minimize energy consumption. Recent advances have created a rapid rise in new electrocatalysts, particularly those based on non-precious metals. In this review, we present a comprehensive overview of the recent developments of ternary and quaternary 6d-group transition metal chalcogenides (TMCs) based electrocatalysts for water splitting, especially for HER. Detailed discussion is organized from binary to quaternary TMCs including, surface engineering, heterostructures, chalcogen substitutions, and hierarchically structural design in TMCs. Moreover, emphasis is placed on future research scope and important challenges facing these electrocatalysts for further development in their performance towards water splitting.  

scholarly journals Layered Ternary and Quaternary Transition Metal Chalcogenide Based Catalysts for Water Splitting

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 551 ◽  
Author(s):  
Anand Tiwari ◽  
Travis Novak ◽  
Xiuming Bu ◽  
Johnny Ho ◽  
Seokwoo Jeon
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Surface Engineering ◽  
Precious Metals ◽  
Future Research ◽  
Metal Chalcogenides ◽  
Comprehensive Overview ◽  
Energy Devices ◽  
Recent Developments ◽  
Electrochemical Water Splitting

Water splitting plays an important role in the electrochemical and photoelectrochemical conversion of energy devices. Electrochemical water splitting by the hydrogen evolution reaction (HER) is a straightforward route to producing hydrogen (H2), which requires an efficient electrocatalyst to minimize energy consumption. Recent advances have created a rapid rise in new electrocatalysts, particularly those based on non-precious metals. In this review, we present a comprehensive overview of the recent developments of ternary and quaternary 6d-group transition metal chalcogenides (TMCs) based electrocatalysts for water splitting, especially for HER. Detailed discussion is organized from binary to quaternary TMCs including, surface engineering, heterostructures, chalcogen substitutions and hierarchically structural design in TMCs. Moreover, emphasis is placed on future research scope and important challenges facing these electrocatalysts for further development in their performance towards water splitting.

Increasing the active sites and intrinsic activity of transition metal chalcogenide electrocatalysts for enhanced water splitting

2020 ◽  
Vol 8 (48) ◽  
pp. 25465-25498
Author(s):  
Jingbin Huang ◽  
Yan Jiang ◽  
Tianyun An ◽  
Minhua Cao
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Active Sites ◽  
Intrinsic Activity ◽  
Metal Chalcogenides ◽  
Metal Chalcogenide ◽  
Transition Metal Chalcogenides

Strategies for enhancing the electrocatalytic activities of transition metal chalcogenides by increasing the number of active sites and intrinsic activity.

Probing the active sites of newly predicted stable Janus scandium dichalcogenides for photocatalytic water-splitting

2019 ◽  
Vol 9 (18) ◽  
pp. 4981-4989 ◽  
Author(s):  
Xiaoyong Yang ◽  
Amitava Banerjee ◽  
Rajeev Ahuja
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Precious Metal ◽  
Active Sites ◽  
Transition Metal Dichalcogenides ◽  
Photocatalytic Water Splitting ◽  
Metal Dichalcogenides

The Janus structures of transition metal dichalcogenides with intrinsic dipoles have recently drawn attention as efficient candidates in the class of non-precious metal photocatalysts for water splitting.

scholarly journals Recent Achievements in Development of TiO2-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1338 ◽  
Author(s):  
Klara Perović ◽  
Francis M. dela Rosa ◽  
Marin Kovačić ◽  
Hrvoje Kušić ◽  
Urška Lavrenčič Štangar ◽  
...  
Keyword(s):  
Water Treatment ◽  
Transition Metal ◽  
Photocatalytic Degradation ◽  
Water Splitting ◽  
Water Purification ◽  
Degradation Mechanism ◽  
Living Environment ◽  
Solar Irradiation ◽  
Metal Chalcogenides ◽  
Photocatalytic Water Splitting

Clean water and the increased use of renewable energy are considered to be two of the main goals in the effort to achieve a sustainable living environment. The fulfillment of these goals may include the use of solar-driven photocatalytic processes that are found to be quite effective in water purification, as well as hydrogen generation. H2 production by water splitting and photocatalytic degradation of organic pollutants in water both rely on the formation of electron/hole (e−/h+) pairs at a semiconducting material upon its excitation by light with sufficient photon energy. Most of the photocatalytic studies involve the use of TiO2 and well-suited model compounds, either as sacrificial agents or pollutants. However, the wider application of this technology requires the harvesting of a broader spectrum of solar irradiation and the suppression of the recombination of photogenerated charge carriers. These limitations can be overcome by the use of different strategies, among which the focus is put on the creation of heterojunctions with another narrow bandgap semiconductor, which can provide high response in the visible light region. In this review paper, we report the most recent advances in the application of TiO2 based heterojunction (semiconductor-semiconductor) composites for photocatalytic water treatment and water splitting. This review article is subdivided into two major parts, namely Photocatalytic water treatment and Photocatalytic water splitting, to give a thorough examination of all achieved progress. The first part provides an overview on photocatalytic degradation mechanism principles, followed by the most recent applications for photocatalytic degradation and mineralization of contaminants of emerging concern (CEC), such as pharmaceuticals and pesticides with a critical insight into removal mechanism, while the second part focuses on fabrication of TiO2-based heterojunctions with carbon-based materials, transition metal oxides, transition metal chalcogenides, and multiple composites that were made of three or more semiconductor materials for photocatalytic water splitting.

scholarly journals The Effect of Iron Impurities on Transition Metal Catalysts for the Oxygen Evolution Reaction in Alkaline Environment: Activity Mediators or Active Sites?

2020 ◽  
Author(s):  
Ioannis Spanos ◽  
Justus Masa ◽  
Aleksandar Zeradjanin ◽  
Robert Schlögl
Keyword(s):  
Transition Metal ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Active Sites ◽  
Water Electrolysis ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Alkaline Water Electrolysis ◽  
Co Catalysts ◽  
Model Transition

AbstractThere is an ongoing debate on elucidating the actual role of Fe impurities in alkaline water electrolysis, acting either as reactivity mediators or as co-catalysts through synergistic interaction with the main catalyst material. This perspective summarizes the most prominent oxygen evolution reaction (OER) mechanisms mostly for Ni-based oxides as model transition metal catalysts and highlights the effect of Fe incorporation on the catalyst surface in the form of impurities originating from the electrolyte or co-precipitated in the catalyst lattice, in modulating the OER reaction kinetics, mechanism and stability. Graphic Abstract

Advancing the extended roles of 3D transition metal based heterostructures with copious active sites for electrocatalytic water splitting

2021 ◽  
Vol 50 (38) ◽  
pp. 13176-13200
Author(s):  
Kannimuthu Karthick ◽  
Selvasundarasekar Sam Sankar ◽  
Sangeetha Kumaravel ◽  
Arun Karmakar ◽  
Ragunath Madhu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Active Sites ◽  
Metal Hydroxides ◽  
Metal Phosphides

This review highlights the importance of 3D transition metal based heterostructures with improved active sites for metal hydroxides, LDHs, oxides, sulfides and metal phosphides and the influencing roles of 3D foams in water splitting.

Valence-Mending Passivation of Si(100) Surface: Principle, Practice and Application

2015 ◽  
Vol 242 ◽  
pp. 51-60 ◽  
Author(s):  
Meng Tao
Keyword(s):  
Transition Metal ◽  
Schottky Barrier Height ◽  
New Records ◽  
Transition Metal Dichalcogenides ◽  
Surface States ◽  
Atomic Layer ◽  
Schottky Barriers ◽  
Photovoltaic Devices ◽  
Dangling Bonds ◽  
Metal Dichalcogenides

Surface states have hindered and degraded many semiconductor devices since the Bardeen era. Surface states originate from dangling bonds on the surface. This paper discusses a generic solution to surface states, i.e. valence-mending passivation. For the Si (100) surface, a single atomic layer of valence-mending sulfur, selenium or tellurium can terminate ~99% of the dangling bonds, while group VII fluorine or chlorine can terminate the remaining 1%. Valence-mending passivation of Si (100) has been demonstrated using CVD, MBE and solution passivation. The keys to valence-mending passivation include an atomically-clean Si (100) surface for passivation and precisely one monolayer of valence-mending atoms on the surface. The passivated surface exhibits unprecedented properties. Electronically the Schottky barrier height between various metals and valence-mended Si (100) now follows more closely the Mott-Schottky theory. With metals of extreme workfunctions, new records for low and high Schottky barriers are created on Si (100). The highest barrier so far is 1.14 eV, i.e. a larger-than-bandgap barrier, and the lowest barrier is below 0.08 eV and potentially negative. Chemically silicidation between metal and valence-mended Si (100) is suppressed up to 500 °C, and the thermally-stable record Schottky barriers enable their applications in nanoelectronic, optoelectronic and photovoltaic devices. Another application is transition metal dichalcogenides. Valence-mended Si (100) is an ideal starting surface for growth of dichalcogenides, as it provides only van der Waals bonding to the dichalcogenide.

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