Non-Metal-Doped Porous Carbon Nitride Nanostructures for Photocatalytic Green Hydrogen Production

Abstract

Photocatalytic green hydrogen (H2) production through water electrolysis is deemed as green, efficient, and renewable fuel or energy carrier due to its great energy density and zero greenhouse emissions. However, developing efficient and low-cost noble-metal-free photocatalysts remains one of the daunting challenges in low-cost H2 production. Porous graphitic carbon nitride (gCN) nanostructures have drawn broad multidisciplinary attention as metal-free photocatalysts in the arena of H2 production and other environmental remediation. This is due to their impressive catalytic/photocatalytic properties (i.e., high surface area, narrow bandgap, and visible light absorption), unique physicochemical durability, tunable electronic properties, and feasibility to synthesize in high yield from inexpensive and earth-abundant resources. The physicochemical and photocatalytic properties of porous gCNs can be easily optimized via the integration of earth-abundant heteroatoms. Although there are various reviews on porous gCN-based photocatalysts for various applications, to the best of our knowledge, there are no reviews on heteroatom-doped porous gCN nanostructures for the photocatalytic H2 evolution reaction (HER). It is essential to provide timely updates in this research area to highlight the research related to fabrication of novel gCNs for large-scale applications and address the current barriers in this field. This review emphasizes a panorama of recent advances in the rational design of heteroatom (i.e., P, O, S, N, and B)-doped porous gCN nanostructures including mono, binary, and ternary dopants for photocatalytic HERs and their optimized parameters. This is in addition to H2 energy storage, non-metal configuration, HER fundamental, mechanism, and calculations. This review is expected to inspire a new research entryway to the fabrication of porous gCN-based photocatalysts with ameliorated activity and durability for practical H2 production.

Synergistically interactive MnFeM (M = Cu, Ti, and Co) sites doped porous g-C3N4 fiber-like nanostructures for an enhanced green hydrogen production

“…The hydrogen evolution reaction (HER) through water splitting is one of the most promising, efficient, eco-friendly, and renewable energy sources due to its exceptional gravimetric energy density, earth-abundant resources, zero-emission combustion, and various production methods. 9–11 Hydrogen production methods like coal gasification and steam reforming 12,13 comprise excessive consumption of energy ( i.e. , 700–1100 °C and 3–25 bar) and fuels ( i.e.…”

“…, CO 2 and CO), while green H 2 production through the HER occurs at room temperature and atmospheric pressure without environmental pollution. 9–11 However, with the aggravation of challenges in HER by using costly and rare-earth Pt-group catalysts, 14–18 it is necessary to exploit low-cost, green, and efficient catalysts to make the HER a competitive energy source on a commercial scale. Dedicated research efforts have come up with Pt-free catalysts, including metal nitrides, sulfides, phosphides, and oxides or their composites ( i.e.…”

“…8 The hydrogen evolution reaction (HER) through water splitting is one of the most promising, efficient, eco-friendly, and renewable energy sources due to its exceptional gravimetric energy density, earth-abundant resources, zero-emission combustion, and various production methods. [9][10][11] Hydrogen production methods like coal gasification and steam reforming 12,13 comprise excessive consumption of energy (i.e., 700-1100 °C and 3-25 bar) and fuels (i.e., natural gas), besides gas emissions (i.e., CO 2 and CO), while green H 2 production through the HER occurs at room temperature and atmospheric pressure without environmental pollution. [9][10][11] However, with the aggravation of challenges in HER by using costly and rareearth Pt-group catalysts, [14][15][16][17][18] it is necessary to exploit low-cost, green, and efficient catalysts to make the HER a competitive energy source on a commercial scale.…”

“…[9][10][11] Hydrogen production methods like coal gasification and steam reforming 12,13 comprise excessive consumption of energy (i.e., 700-1100 °C and 3-25 bar) and fuels (i.e., natural gas), besides gas emissions (i.e., CO 2 and CO), while green H 2 production through the HER occurs at room temperature and atmospheric pressure without environmental pollution. [9][10][11] However, with the aggravation of challenges in HER by using costly and rareearth Pt-group catalysts, [14][15][16][17][18] it is necessary to exploit low-cost, green, and efficient catalysts to make the HER a competitive energy source on a commercial scale. Dedicated research efforts have come up with Pt-free catalysts, including metal nitrides, sulfides, phosphides, and oxides or their composites (i.e., Ni-Fe-P/NF 30 , NP-NiCo 2 O 4 , MoS 2 , and CoP 3 ).…”

Reasonable Design of MXene-Supported Dual-Atom Catalysts with High Catalytic Activity for Hydrogen Evolution and Oxygen Evolution Reaction: A First-Principles Investigation

“…Water splitting technology is debated as the most prospective and sustainable way to produce hydrogen and oxygen, which involves hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Up to now, the expensive noble metals or their oxides are still deemed as the best choice to propel these reactions, where Pt is used for HER and RuO 2 /IrO 2 is used for OER [ 9 , 10 , 11 ].…”