Recent progress in enhancing solar-to-hydrogen efficiency

Chen, Jianqing; Yang, Donghui; Song, Dan; Jiang, Jinghua; Ma, Aibin; Hu, Michael Z.; Ni, Chaoying

doi:10.1016/j.jpowsour.2015.01.073

Cited by 116 publications

(79 citation statements)

References 253 publications

(252 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These efficiencies are amongst the highest reported in combination with dispersed co-catalysts, including those obtained with inorganic semiconductors. 13 The molecular formula, C 3 N 4 , which is widely used in the literature, represents a fully polymerized graphitic carbon nitride (graphitic PCN) with either tri-s-triazine (also called heptazine, gh-C 3 N 4 ) or triazine (gt-C 3 N 4 ) as repeating units. 14 Semi-crystalline PCNs are generally prepared by thermal polymerization of precursors, such as cyanamide, urea or melamine.…”

Section: Polymeric Carbon Nitridesmentioning

confidence: 99%

Shining Light on Carbon Nitrides: Leveraging Temperature To Understand Optical Gap Variations

Melissen

Bahers

et al. 2018

Chem. Mater.

View full text Add to dashboard Cite

Polymeric carbon nitride (PCN)-based materials have opened new research avenues in the photocatalytic field. The understanding of parameters underlying the optical properties of PCNs is critical to improve their performance. Herein, the optical properties of PCNs are investigated with a combination of Time-Dependent Density Functional Theory (TD-DFT) calculations and laboratory characterizations, including Variable Temperature (VT)-XRD, VT-UV-Vis and VT-IR techniques, on samples prepared using a broad range of synthesis temperatures. Upon increasing the synthesis temperature from 390 to 600°C, the optical gap E opt g (eV) narrows from 2.92 to 2.67, and on further increasing the synthesis temperature to 700°C, widens to 3.03 and another absorption at ∼2.2 eV is observed. The TD-DFT calculations show that E opt g of PCNs converges rapidly with heptazine oligomer size, indicating localized photophysics behavior and justifying a molecular approach. Calculations exploring geometrical variations upon increasing the temperature at which the optical properties were determined revealed that the net effect of these variations were limited, suggesting a vibrational origin of the observed decrease in the gap. The absorption at ∼2.2 eV is tentatively attributed to fully polymerized graphitic PCN oligomers as suggested by the excitation wavelength-dependent photoluminescence emission behavior. The results provide novel insights into the optical properties of PCNs, providing directions for the development of the next generation of PCN-based photocatalysts with optimal light harvesting abilities.

show abstract

Section: Polymeric Carbon Nitridesmentioning

confidence: 99%

Shining Light on Carbon Nitrides: Leveraging Temperature To Understand Optical Gap Variations

Melissen

Bahers

et al. 2018

Chem. Mater.

View full text Add to dashboard Cite

show abstract

“…Water splitting seems to be one of the most convenient ways to reach this goal. [1][2][3] Hydrogen could play a very important role due to its potential use in clean energy applications. 4 As a consequence, achieving high efficiency in solar water photosplitting would contribute to convert our fossil fuel dependent society into another one whose development would be based on renewable energy.…”

mentioning

confidence: 99%

Sol–gel copper chromium delafossite thin films as stable oxide photocathodes for water splitting

2015

View full text Add to dashboard Cite

show abstract

“…The capture and conversion of solar energy to drive photocatalytic hydrogen production would provide a clean alternative energy solution that can be used to generate useful chemical fuels Honda and Fujishima were the first to demonstrate the decomposition of H 2 O into H 2 and O 2 using TiO 2 as an n-type photocatalyst [76]. Since this groundbreaking work, semiconductor-based photocatalytic water splitting to produce hydrogen has been considered one of the most important approaches to solving the world energy crisis [77]. Semiconductors have also been used in practical application for the photocatalytic degradation of organic pollutants in water [78][79][80][81].…”

Section: Introductionmentioning

confidence: 99%

Polymorphism and Structural Distortions of Mixed-Metal Oxide Photocatalysts Constructed with α-U3O8 Types of Layers

et al. 2017

View full text Add to dashboard Cite

Abstract:A series of mixed-metal oxide structures based on the stacking of α-U 3 O 8 type pentagonal bipyramid layers have been investigated for symmetry lowering distortions and photocatalytic activity. The family of structures contains the general composition A m+ ((n+1)/m) B (3n+1) O (8n+3) (e.g., A = Ag, Bi, Ca, Cu, Ce, Dy, Eu, Gd K, La, Nd, Pb, Pr, Sr, Y; B = Nb, Ta; m = 1-3; n = 1, 1.5, 2), and the edge-shared BO 7 pentagonal pyramid single, double, and/or triple layers are differentiated by the average thickness, (i.e., 1 ≤ n ≤ 2), of the BO 7 layers and the local coordination environment of the "A" site cations. Temperature dependent polymorphism has been investigated for structures containing single layered (n = 1) monovalent (m = 1) "A" site cations (e.g., Ag 2 Nb 4 O 11 , Na 2 Nb 4 O 11 , and Cu 2 Ta 4 O 11 ). Furthermore, symmetry lowering distortions were observed for the Pb ion-exchange synthesis of Ag 2 Ta 4 O 11 to yield PbTa 4 O 11 . Several members within the subset of the family have been constructed with optical and electronic properties that are suitable for the conversion of solar energy to chemical fuels via water splitting.

show abstract

Recent progress in enhancing solar-to-hydrogen efficiency

Cited by 116 publications

References 253 publications

Shining Light on Carbon Nitrides: Leveraging Temperature To Understand Optical Gap Variations

Shining Light on Carbon Nitrides: Leveraging Temperature To Understand Optical Gap Variations

Sol–gel copper chromium delafossite thin films as stable oxide photocathodes for water splitting

Polymorphism and Structural Distortions of Mixed-Metal Oxide Photocatalysts Constructed with α-U3O8 Types of Layers

Contact Info

Product

Resources

About