scholarly journals In Situ Construction of Ag/TiO2/g-C3N4 Heterojunction Nanocomposite Based on Hierarchical Co-Assembly with Sustainable Hydrogen Evolution

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
Rui Geng ◽  
Juanjuan Yin ◽  
Jingxin Zhou ◽  
Tifeng Jiao ◽  
Yao Feng ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Self Assembly ◽  
Active Sites ◽  
Carrier Transport ◽  
Synergistic Effects ◽  
Electron Hole ◽  
Simple Strategy ◽  
Promising Strategy ◽  
Catalytic Active Sites

The construction of heterojunctions provides a promising strategy to improve photocatalytic hydrogen evolution. However, how to fabricate a nanoscale TiO2/g-C3N4 heterostructure and hinder the aggregation of bulk g-C3N4 using simple methods remains a challenge. In this work, we use a simple in situ construction method to design a heterojunction model based on molecular self-assembly, which uses a small molecule matrix for self-integration, including coordination donors (AgNO3), inorganic titanium source (Ti(SO4)2) and g-C3N4 precursor (melamine). The self-assembled porous g-C3N4 nanotube can hamper carrier aggregation and it provides numerous catalytic active sites, mainly via the coordination of Ag+ ions. Meanwhile, the TiO2 NPs are easily mineralized on the nanotube template in dispersive distribution to form a heterostructure via an N–Ti bond of protonation, which contributes to shortening the interfacial carrier transport, resulting in enhanced electron-hole pairs separation. Originating from all of the above synergistic effects, the obtained Ag/TiO2/g-C3N4 heterogenous photocatalysts exhibit an enhanced H2 evolution rate with excellent sustainability 20.6-fold-over pure g-C3N4. Our report provides a feasible and simple strategy to fabricate a nanoscale heterojunction incorporating g-C3N4, and has great potential in environmental protection and water splitting.

Engineering of Ru/Ru2P interfaces superior to Pt active sites for catalysis of the alkaline hydrogen evolution reaction

2019 ◽  
Vol 7 (10) ◽  
pp. 5621-5625 ◽  
Author(s):  
Zhao Liu ◽  
Zhe Li ◽  
Jing Li ◽  
Jie Xiong ◽  
Shunfa Zhou ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Synergistic Effects ◽  
Water Dissociation ◽  
Proton Reduction ◽  
Mass Activity

Based on the synergistic effects of Ru on water dissociation and Ru2P on proton reduction, Ru/Ru2P interfaces were engineered in situ, and the mass activity of the new catalyst for the alkaline HER was doubled compared to Pt/C.

scholarly journals Electrochemically Induced In-Situ Generated Co(OH)2 Nanoplates to Promote the Volmer Process Toward Efficient Alkaline Hydrogen Evolution Reaction

2020 ◽  
Author(s):  
Hong Liu ◽  
Jian-Jun Wang ◽  
Li-Wen Jiang ◽  
Yuan Huang ◽  
Bing Bing Chen ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Water Electrolysis ◽  
Water Dissociation ◽  
Alkaline Water Electrolysis ◽  
Additional Water ◽  
Dissociation Step ◽  
Insight Into

<p>Hydrogen production via alkaline water electrolysis is of significant interest. However, the additional water dissociation step makes the Volmer step a relatively more sluggish kinetics and consequently leads to a slower reaction rate than that in acidic solution. Herein, we demonstrate an effective strategy that Co(OH)<sub>2</sub> can promote the Volmer process by accelerating water dissociation and enhance the electrocatalytic performance of CoP toward alkaline hydrogen evolution reaction. The Co(OH)<sub>2</sub> nanoplates are electrochemically induced in-situ generated to form a nanotree-like structure with porous CoP nanowires, endowing the hybrid electrocatalyst with superior charge transportation, more exposed active sites, and enhanced reaction kinetics. This strategy may be extended to <a></a><a>other phosphides and chalcogenides </a>and provide insight into the design and fabrication of efficient alkaline HER catalysts.</p>

scholarly journals Identifying Catalytic Active Sites of Trimolybdenum Phosphide (Mo 3 P) for Electrochemical Hydrogen Evolution

2019 ◽  
Vol 9 (39) ◽  
pp. 1902639
Author(s):  
Alireza Kondori ◽  
Mohammadreza Esmaeilirad ◽  
Artem Baskin ◽  
Boao Song ◽  
Jialiang Wei ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Active Sites ◽  
Catalytic Active Sites

Triphenylamine and terpyridine–zinc(ii) complex based donor–acceptor soft hybrid as a visible light-driven hydrogen evolution photocatalyst

2020 ◽  
Vol 8 (42) ◽  
pp. 21968-21972
Author(s):  
Debabrata Samanta ◽  
Manish Kumar ◽  
Sugandha Singh ◽  
Parul Verma ◽  
Kamal K. Kar ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Visible Light ◽  
Hydrogen Evolution ◽  
Self Assembly ◽  
Visible Light Driven ◽  
Donor Acceptor

A donor–acceptor coordination polymer (TPA-Zn) was synthesized by Zn(ii)-assisted self-assembly of an in situ generated triphenylamine (TPA) cored tristerpyridine ligand.

scholarly journals Electrochemically Induced In-Situ Generated Co(OH)2 Nanoplates to Promote the Volmer Process Toward Efficient Alkaline Hydrogen Evolution Reaction

2020 ◽  
Author(s):  
Hong Liu ◽  
Jian-Jun Wang ◽  
Li-Wen Jiang ◽  
Yuan Huang ◽  
Bing Bing Chen ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Water Electrolysis ◽  
Water Dissociation ◽  
Alkaline Water Electrolysis ◽  
Additional Water ◽  
Dissociation Step ◽  
Insight Into

<p>Hydrogen production via alkaline water electrolysis is of significant interest. However, the additional water dissociation step makes the Volmer step a relatively more sluggish kinetics and consequently leads to a slower reaction rate than that in acidic solution. Herein, we demonstrate an effective strategy that Co(OH)<sub>2</sub> can promote the Volmer process by accelerating water dissociation and enhance the electrocatalytic performance of CoP toward alkaline hydrogen evolution reaction. The Co(OH)<sub>2</sub> nanoplates are electrochemically induced in-situ generated to form a nanotree-like structure with porous CoP nanowires, endowing the hybrid electrocatalyst with superior charge transportation, more exposed active sites, and enhanced reaction kinetics. This strategy may be extended to <a></a><a>other phosphides and chalcogenides </a>and provide insight into the design and fabrication of efficient alkaline HER catalysts.</p>

scholarly journals How Stable Are 2H-MoS2 Edges Under Hydrogen Evolution Reaction Conditions?

2021 ◽  
Author(s):  
Nawras Abidi ◽  
Audrey Bonduelle-Skrzypczak ◽  
Stephan Steinmann
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
External Source ◽  
Operating Conditions ◽  
Adsorbed Hydrogen ◽  
Functional Theory ◽  
Acidic Conditions

MoS<sub>2</sub>, have emerged as a promising class of electrocatalysts for the production of H<sub>2</sub> via the hydrogen evolution reaction (HER) in acidic conditions.<div>The edges of MoS<sub>2</sub> are known for their HER activity, but their precise atomistic nature and stability under HER conditions is not yet known. In contrast to other typical uses of MoS<sub>2</sub> as a catalyst, under HER there is no external source of sulfur. Therefore, the sulfidation of the edges can only decrease under operating conditions and the thermodynamics of the process are somewhat ill-defined. Our results suggest that the 50%S S-edge may be active for HER via the Volmer-Tafel mechanism and is, despite a high H coverage, stable with respect to H<sub>2</sub>S release. </div><div>At the 50%S Mo-edge, the adsorbed hydrogen opens the way for H<sub>2</sub>S release, leading to the 0%S Mo-edge, which was previously investigated and found to be HER active. HER being a water-based process, we also considered the effect of the presence of H<sub>2</sub>O and the in-situ formation of OH. For the 50%S Mo-edge, H<sub>2</sub>O is only very weakly adsorbed and OH formation is unfavorable. Nevertheless, OH assists the loss of sulfur coverage, leading to OH-based HER active sites. In contrast, OH is strongly adsorbed on the 50%S S-edge. By explicitly considering the electrochemical potential using grand-canonical density functional theory, we unveil that the Volmer-Heyrovsky mechanism on sulfur sites is still accessible in the presence of surface OH at the 50%S S-edge. However, the 50%S S-edge is found to be mildly unstable with respect to H<sub>2</sub>S in the presence of water/OH. Hence, we suggest that the 50%S S-edge evolves over time towards a 0%S S-edge, covered by surface OH that will block permanently the active sites. </div>

Interfacial synergy of ultralong jagged Pt85Mo15–S nanowires with abundant active sites on enhanced hydrogen evolution in an alkaline solution

2019 ◽  
Vol 7 (42) ◽  
pp. 24328-24336 ◽  
Author(s):  
Yao Wang ◽  
Hongying Zhuo ◽  
Xin Zhang ◽  
Yunrui Li ◽  
Juntao Yang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Alkaline Solution ◽  
Active Sites ◽  
Synergistic Effects

Ultralong jagged PtMo–S nanowires with rich “interfacial active sites” were fabricated by using S as the “active auxiliary” to demonstrate the enhanced catalytic HER performance triggered by the electronic and synergistic effects of PtMo/MoSx.

Fluorination Activates the Basal Plane HER Activity of ReS2: A Combined Experimental and Theoretical Study

2021 ◽  
Author(s):  
Yonggang Liu ◽  
Haijing Li ◽  
Junfu Li ◽  
Xiaoshuang Ma ◽  
Zhiming Cui ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Basal Plane ◽  
Active Sites ◽  
Theoretical Study ◽  
Two Dimensional ◽  
Catalytic Active Sites

Two-dimensional (2D) rhenium disulfide (ReS2) has been attracting immense interests as highly promising hydrogen evolution reaction (HER) electrocatalyst recently. However, the HER catalytic active sites of ReS2 are still limited...

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