Recent Trends in Graphitic Carbon Nitride-Based Binary and Ternary Heterostructured Electrodes for Photoelectrochemical Water Splitting

Abstract

The graphitic carbon nitride (g-C3N4) is a class of two-dimensional layered material. The ever-growing research on this fascinating material is due to its unique visible light absorption, surface, electrocatalytic, and other physicochemical properties that can be useful to different energy conversion and storage applications. Photoelectrochemical (PEC) water splitting reaction is one of the promising applications of g-C3N4, wherein it acts as a durable catalyst support material. Very recently, the construction of g-C3N4-based binary and ternary heterostructures exhibited superior PEC water splitting performance owing to its reduced reunion of e-/h+ pairs and the fast transfer of charge carriers at the heterostructure interface. This review compiles the recent advances and challenges on g-C3N4-based heterostructured photocatalysts for the PEC water splitting reaction. After an overview of the available literature, we presume that g-C3N4-based photocatalysts showed enhanced PEC water splitting performance. Therefore, it is believed that these materials have tremendous opportunities to act as durable catalyst support for energy-related applications. However, researchers also considered several limitations and challenges for using C3N4 as an efficient catalyst support material that must be addressed. This review article provides an overview of the fundamental principles of PEC water splitting, the current PEC water splitting research trends on g-C3N4-based binary and ternary heterostructured electrodes with respect to different electrolytes, and the other key factors influencing their photoelectrochemical performance. Finally, the future research direction with several recommendations to improve the photocatalytic efficiency of these materials is also provided at the end.

A review on the advancements of graphitic carbon nitride-based photoelectrodes for photoelectrochemical water splitting

“…In the case of n-type semiconductors, we have an upward bending while a downward bending is observed for p-type materials. [38][39][40][41][42] In short, the transfer of electrons to the electrolyte by a p-type semiconductor generates a cathodic photocurrent, while an anodic photocurrent is produced when holes are received by the electrolyte aided by an n-type semiconductor. 53 The electrons generated at the CB of the photocathode directly migrate to the electrode surface, reducing H + to H 2 , while holes are transported to the anode for water oxidation.…”

“…The photocurrent responses of carbon nitride solids were first reported by Zhang et al 38 in 2010, paving a new path for PEC applications. 39 Several reports covering various aspects of g-C 3 N 4 -based PEC water splitting are available in the literature, [39][40][41][42][43][44][45] most of which are primarily focused on film fabrication strategies. In this review, we provide a concise depiction of the basic principles of photoelectrochemical water splitting.…”

Review—Strategic Design of Layered Double Hydroxides and Graphitic Carbon Nitride Heterostructures for Photoelectrocatalytic Water Splitting Applications

“…53,168,174,200,201 The exceptional catalytic activity associated with g-C 3 N 4 and their hybrid materials is due to their intercalation, ion exchange, and oxidation/reduction properties. 168,174,188,[202][203][204][205] A schematic diagram of g-C 3 N 4 as a photoanode in photoelectrochemical (PEC)half-cell for water splitting is shown in Fig. 4.…”

“…181 Hybrid 2D-2D heterostructures of g-C 3 N 4 and LDH.-The coupling of 2D material g-C 3 N 4 with layered semiconductors improves the overall photocatalytic properties. 32,116,168,174,177,194,201,202,204,[206][207][208][209][210][211] For this purpose, g-C 3 N 4 is coupled with layered double hydroxides (LDH) because of the structural and functional similarities between these two materials. 46,66,67,98,102,109,116,146,[212][213][214][215][216][217][218][219][220][221] The addition of g-C 3 N 4 enhances the surface area, photostability, and photoactivity of the LDH material because of the highly stable delocalized conjugated structure of g-C 3 N 4 .…”

Large-scale sonochemical fabrication of a Co3O4–CoFe2O4@MWCNT bifunctional electrocatalyst for enhanced OER/HER performances

“…31 Several methods have been suggested for fabricating mixed-phase binary and ternary nanocomposite (solid-state, sol-gel, hydrothermal, co-precipitation, etc.). [32][33][34][35] The benets of ultrasonic irradiation synthesis include large-scale synthesis, reduced reaction times, smaller product sizes, more precise control over synthesis conditions, less manufacturing costs, higher grade standards, less environmental effect, and so on. 36 Acoustic cavitation, the process by which bubbles form, expand, and then combust as a result of ultrasound irradiation, is responsible for most of the chemical effects of this type of irradiation.…”