Immobilized Covalent Triazine Frameworks Films as Effective Photocatalysts for Hydrogen Evolution Reaction

2021 ◽  
Author(s):  
Xunliang Hu ◽  
Irshad Hussain ◽  
Bien Tan
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Crystalline Structure ◽  
Large Scale ◽  
Interfacial Polymerization ◽  
Point Of View ◽  
Lateral Size ◽  
Free Standing ◽  
X Ray ◽  
Synthetic Approaches

Abstract Covalent triazine frameworks (CTFs) have recently been demonstrated as promising materials for photocatalytic water splitting and are usually used in the form of suspended powder. From a practical point of view, immobilized CTFs materials are more suitable for large-scale water splitting applications, owing to their convenient separation and recycling potential. However, existing synthetic approaches mainly result in insoluble and unprocessable powders, which makes their future device application still a huge challenge. Herein, we report an aliphatic amine-assisted interfacial polymerization method to obtain free-standing, crystalline CTFs film with excellent photoelectric performance. The lateral size of the film was up to 250 cm2, the average thickness can be regulated from 30-500 nm. The crystalline structure was confirmed by high-resolution transmission electron microscope (HR-TEM), powder X-ray diffraction (PXRD), and small-angle X-ray scattering (SAXS) analysis. Intrigued by the good light absorption, crystalline structure, and big lateral size of the film, it was immobilized on a glass support that exhibited good photocatalytic hydrogen evolution performance (5.4 mmol h-1 m-2) and was easy to recycle.

scholarly journals Immobilized covalent triazine frameworks films as effective photocatalysts for hydrogen evolution reaction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xunliang Hu ◽  
Zhen Zhan ◽  
Jianqiao Zhang ◽  
Irshad Hussain ◽  
Bien Tan
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Large Scale ◽  
Interfacial Polymerization ◽  
Lateral Size ◽  
Free Standing ◽  
X Ray ◽  
X Ray Scattering ◽  
Formidable Challenge ◽  
Ray Scattering

AbstractCovalent triazine frameworks have recently been demonstrated as promising materials for photocatalytic water splitting and are usually used in the form of suspended powder. From a practical point of view, immobilized CTFs materials are more suitable for large-scale water splitting, owing to their convenient separation and recycling potential. However, existing synthetic approaches mainly result in insoluble and unprocessable powders, which make their future device application a formidable challenge. Herein, we report an aliphatic amine-assisted interfacial polymerization method to obtain free-standing, semicrystalline CTFs film with excellent photoelectric performance. The lateral size of the film was up to 250 cm2, and average thickness can be tuned from 30 to 500 nm. The semicrystalline structure was confirmed by high-resolution transmission electron microscope, powder X-ray diffraction, grazing-incidence wide-angle X-ray scattering, and small-angle X-ray scattering analysis. Intrigued by the good light absorption, crystalline structure, and large lateral size of the film, the film immobilized on a glass support exhibited good photocatalytic hydrogen evolution performance (5.4 mmol h−1 m−2) with the presence of co-catalysts i.e., Pt nanoparticles and was easy to recycle.

scholarly journals The Synergistic Effects of Alloying on the Performance and Stability of Co3Mo and Co7Mo6 for the Electrocatalytic Hydrogen Evolution Reaction

Hydrogen ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 11-21
Author(s):  
Youyi Sun ◽  
Alexey Y. Ganin
Keyword(s):  
Hydrogen Evolution ◽  
Synergistic Effects ◽  
Alkaline Media ◽  
Price Of Stability ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Current Decay ◽  
Earth Abundant ◽  
Current Densities

Metal alloys have become a ubiquitous choice as catalysts for electrochemical hydrogen evolution in alkaline media. However, scarce and expensive Pt remains the key electrocatalyst in acidic electrolytes, making the search for earth-abundant and cheaper alternatives important. Herein, we present a facile and efficient synthetic route towards polycrystalline Co3Mo and Co7Mo6 alloys. The single-phased nature of the alloys is confirmed by X-ray diffraction and electron microscopy. When electrochemically tested, they achieve competitively low overpotentials of 115 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 0.5 M H2SO4, and 120 mV (Co3Mo) and 160 mV (Co7Mo6) at 10 mA cm−2 in 1 M KOH. Both alloys outperform Co and Mo metals, which showed significantly higher overpotentials and lower current densities when tested under identical conditions, confirming the synergistic effect of the alloying. However, the low overpotential in Co3Mo comes at the price of stability. It rapidly becomes inactive when tested under applied potential bias. On the other hand, Co7Mo6 retains the current density over time without evidence of current decay. The findings demonstrate that even in free-standing form and without nanostructuring, polycrystalline bimetallic electrocatalysts could challenge the dominance of Pt in acidic media if ways for improving their stability were found.

Fe-Co-P multi-heterostructure arrays for efficient electrocatalytic water splitting

2021 ◽  
Author(s):  
Hanwen Xu ◽  
Jiawei Zhu ◽  
Pengyan Wang ◽  
Ding Chen ◽  
Chengtian Zhang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Oxygen Evolution Reaction ◽  
Rational Design ◽  
Large Scale ◽  
High Efficiency ◽  
Bifunctional Catalysts

Rational design and construction of high-efficiency bifunctional catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for large-scale hydrogen production by water splitting. Herein, by a...

scholarly journals Facile and Large-scale Synthesis of Defective Black TiO2−x(B) Nanosheets for Efficient Visible-light-driven Photocatalytic Hydrogen Evolution

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1048 ◽  
Author(s):  
JingCheng Xu ◽  
JiaJia Zhang ◽  
ZhengYang Cai ◽  
He Huang ◽  
TianHao Huang ◽  
...  
Keyword(s):  
Visible Light ◽  
Hydrogen Evolution ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Broad Band ◽  
Mass Ratio ◽  
X Ray ◽  
Black Tio2 ◽  
Large Scale Synthesis ◽  
Nabh4 Reduction

In the work, we firstly report the facile and large-scale synthesis of defective black TiO2−x(B) nanosheets via a dual-zone NaBH4 reduction method. The structure, physico-chemical, and optical properties of TiO2−x(B) nanosheets were systematically characterized by powder X-ray diffraction, Raman spectroscopy, UV-Vis absorption spectroscopy, and X-ray photoelectron spectroscopy, etc. The concentration of Ti3+ can be well tuned by NaBH4 reduction. With increasing the mass ratio of NaBH4 to TiO2(B), the generation of Ti3+ defects gives rise to the increased intensity of a broad band absorption in the visible wavelength range. It is demonstrated that the TiO2−x(B) photocatalyst synthesized with the mass ratio of NaBH4 to TiO2(B) of 3:1 exhibited an optimum photocatalytic activity and excellent photostability for hydrogen evolution under visible-light irradiation. By combining the advantages of 2D TiO2(B) nanosheets architecture with those of Ti3+ self-doping and simultaneous production of oxygen vacancy sites, the enhanced photocatalytic performance of the defective TiO2−x(B) nanosheets was achieved.

scholarly journals Revealing the effect of electrocatalytic performance boost during hydrogen evolution reaction on free-standing SWCNT film electrode

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Karolina Kordek-Khalil ◽  
Dawid Janas ◽  
Piotr Rutkowski
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Large Scale ◽  
Carbon Nanomaterials ◽  
Low Cost ◽  
High Surface ◽  
Water Electrolysis ◽  
Free Standing ◽  
Highly Active ◽  
Electrocatalytic Performance

AbstractLarge-scale sustainable hydrogen production by water electrolysis requires a highly active yet low-cost hydrogen evolution reaction (HER) electrocatalyst. Conductive carbon nanomaterials with high surface areas are promising candidates for this purpose. In this contribution, single-walled carbon nanotubes (SWCNTs) are assembled into free-standing films and directly used as HER electrodes. During the initial 20 h of electrocatalytic performance in galvanostatic conditions, the films undergo activation, which results in a gradual overpotential decrease to the value of 225 mV. Transient physicochemical properties of the films at various activation stages are characterized to reveal the material features responsible for the activity boost. Results indicate that partial oxidation of iron nanoparticles encapsulated in SWCNTs is the major contributor to the activity enhancement. Furthermore, besides high activity, the material, composed of only earth-abundant elements, possesses exceptional performance stability, with no activity loss for 200 h of galvanostatic performance at − 10 mA cm−2. In conclusion, the work presents the strategy of engineering a highly active HER electrode composed of widely available elements and provides new insights into the origins of electrocatalytic performance of SWCNT-based materials in alkaline HER.

Interfacial engineering of Mo2C–Mo3C2 heteronanowires for high performance hydrogen evolution reactions

Nanoscale ◽  
2019 ◽  
Vol 11 (48) ◽  
pp. 23318-23329 ◽  
Author(s):  
Lina Jia ◽  
Chen Li ◽  
Yaru Zhao ◽  
Bitao Liu ◽  
Shixiu Cao ◽  
...  
Keyword(s):  
High Activity ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Precious Metal ◽  
High Performance ◽  
Large Scale ◽  
Low Cost ◽  
Critical Importance ◽  
Interfacial Engineering ◽  
Hydrogen Evolution Reactions

Non-precious metal-based electrocatalysts with high activity and stability for efficient hydrogen evolution reactions are of critical importance for low-cost and large-scale water splitting.

Observations of coexistence of FCC and HCP phases in C60 by HREM

1992 ◽  
Vol 50 (1) ◽  
pp. 110-111
Author(s):  
Z.G. Li ◽  
Paul J. Fagan
Keyword(s):  
Carbon Atom ◽  
Crystalline Structure ◽  
Diffraction Data ◽  
Large Scale ◽  
Nearest Neighbor ◽  
Neighbor Distance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hexagonal Close Packed ◽  
Correct Structure

Since the discovery of a large scale synthesis of fullerenes there has been intense interest in the structure of these materials. The first diffraction data suggested that crystalline C60 had a hexagonal close-packed (hep) structure with a nearest neighbor distance of 10.04 Å. The possibility of a disordered stacking of C60 molecules was first noted in this study. Since then, there has been some confusion regarding the exact crystalline structure of C60 as determined by electron and X-ray diffraction. In particular, a diffraction feature corresponding to a spacing of 8.7 Å has been noted in several studies. Recendy there had been a growing consensus that fcc is the correct structure for sublimed C60. Although the internal carbon atom arrangement of the C60 molecules cannot be determined, the actual packing and defects in C60 crystals over small and relatively large regions are readily seen by HRTEM. We have found by direct imaging a relatively large region of defect-free hep packing of C60 spheres sublimed onto a relatively cool microscopy grid.

Silicon Nanowire-Ta2O5-NGQD Heterostructure: An Efficient Photocathode for Photoelectrochemical Hydrogen Evolution

2021 ◽  
Author(s):  
Sk. Riyajuddin ◽  
Jenifar Sultana ◽  
Shumile Ahmed Siddiqui ◽  
Sushil Kumar ◽  
Damini Badhwar ◽  
...  
Keyword(s):  
Solar Energy ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Large Scale ◽  
Silicon Nanowire ◽  
Research Interest ◽  
Hydrogen Fuel ◽  
Environment Friendly ◽  
Pec Water Splitting

Photoelectrochemical (PEC) water splitting propels a broader research interest for large-scale and facile entrapment of solar energy in hydrogen fuel. It offers the most favorable and environment-friendly approach to harvest...

scholarly journals Construction of Ni-Mo-P heterostructures with efficient hydrogen evolution performance under acidic condition

2021 ◽  
Author(s):  
Tian-Yun Chen ◽  
Ya-Qi Zhang ◽  
Ying-Yan Fu ◽  
Min Qian ◽  
Hao-Jiang Dai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Evolution ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Clean Energy ◽  
Hydrogen Energy ◽  
Durability Test ◽  
X Ray ◽  
Onset Potential

Abstract Hydrogen energy is regarded as one of the most important clean energy in the 21st century, and improving the catalytic efficiency of hydrogen evolution reaction (HER) is the basis for realizing the large-scale hydrogen production. Transition metal phosphides (TMPs) were proved to be efficient electrocatalysts for HER. In this work, we first synthesized the nickel-molybdenum bimetallic precursors, followed by high-temperature calcination in air. Finally, NiMoP/MoP nanorods (Ni-Mo-P NRs) was obtained by chemical vapor deposition (CVD) of phosphating. The target catalyst of Ni-Mo-P NRs was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). For Ni-Mo-P NRs, the electrochemical test in 0.5 M H2SO4 solution for HER showed that the optimal feeding ratio was Ni: Mo = 1:1. And the Ni1-Mo1-P NRs presented an onset potential of 63.2 mV, and an overpotential of 117.9 mV was required to drive the current density of 10 mA↔cm− 2. Meanwhile, The Tafel slope, exchange current density (j0), electrochemical double-layer capacitance (Cdl) were 58.6 mV↔dec− 1, 0.10 mA↔cm− 2, 12.6 mF↔cm− 2, respectively. Moreover, there was no obvious activity diminish of Ni1-Mo1-P NRs after a long-term stability and durability test.

scholarly journals An Al-doped SrTiO3 photocatalyst maintaining sunlight-driven overall water splitting activity for over 1000 h of constant illumination

2019 ◽  
Vol 10 (11) ◽  
pp. 3196-3201 ◽  
Author(s):  
Hao Lyu ◽  
Takashi Hisatomi ◽  
Yosuke Goto ◽  
Masaaki Yoshida ◽  
Tomohiro Higashi ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Large Scale ◽  
Constant Illumination ◽  
Solar Hydrogen ◽  
Overall Water Splitting ◽  
Evolution Systems

The development of robust and efficient water splitting photocatalysts overcomes a long-standing barrier to sustainable large-scale solar hydrogen evolution systems.

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