Relation between Water Oxidation Activity and Coordination Environment of C,N-Coordinated Mononuclear Co Catalyst

ACS Catalysis ◽  
2021 ◽  
pp. 491-496
Author(s):  
Qing’e Huang ◽  
Binli Wang ◽  
Sheng Ye ◽  
Hua Liu ◽  
Haibo Chi ◽  
...  
2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Manuel Heimann ◽  
Klaus Friedel Ortega ◽  
Malte Behrens

Abstract The synthesis conditions of the semiconductor BiVO4 have marked influence on its physicochemical and photocatalytic properties. In this work, a pH-controlled co-precipitation route was systematically investigated. Special attention was paid to the pH value during co-precipitation and co-precipitate post-treatment. In a sacrificial photocatalytic water oxidation test, the highest activity was observed for a sample precipitated at pH = 1 and 70 °C, which was post treated at 600 °C in air for 3 h after washing and drying. The activity was further improved by another 90% by the addition of the Co3O4-based co-catalyst. Good synergy between semiconductor and co-catalyst was obtained for the deposition of pre-formed nanoparticles at a loading of 0.1 w% (physical impregnation). The effects of different synthesis conditions of the semiconductor and impregnation method for the co-catalyst on the structure, morphology and optical properties of the catalysts were investigated by PXRD, SEM, UV-vis spectroscopy, and TEM, while the water oxidation activity was compared in the dark and with the aid of visible light using cerium (IV) or silver (I) as sacrificial agents, respectively, with the aim of establishing structure-activity correlations. The roles of semiconductor particle anisotropy and co-catalyst particle distribution for optimal photo-activity in the oxygen evolution reaction are discussed.


Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2221
Author(s):  
Ruilian Qi ◽  
Jian Liu ◽  
Huanxiang Yuan ◽  
Yu Yu

Photocatalysis is a powerful strategy to address energy and environmental concerns. Sulfur-doped BiOCl was prepared through a facial hydrothermal method to improve the photocatalytic performance. Experimental results and theoretical calculations demonstrated that the band structure of the sulfur-doped BiOCl was optimally regulated and the light absorption range was expanded. It showed excellent visible-light photocatalytic water oxidation properties with a rate of 141.7 μmol h−1 g−1 (almost 44 times of that of the commercial BiOCl) with Pt as co-catalyst.


2021 ◽  
Vol 118 (36) ◽  
pp. e2101817118
Author(s):  
Xueli Zheng ◽  
Jing Tang ◽  
Alessandro Gallo ◽  
Jose A. Garrido Torres ◽  
Xiaoyun Yu ◽  
...  

The efficiency of the synthesis of renewable fuels and feedstocks from electrical sources is limited, at present, by the sluggish water oxidation reaction. Single-atom catalysts (SACs) with a controllable coordination environment and exceptional atom utilization efficiency open new paradigms toward designing high-performance water oxidation catalysts. Here, using operando X-ray absorption spectroscopy measurements with calculations of spectra and electrochemical activity, we demonstrate that the origin of water oxidation activity of IrNiFe SACs is the presence of highly oxidized Ir single atom (Ir5.3+) in the NiFe oxyhydroxide under operating conditions. We show that the optimal water oxidation catalyst could be achieved by systematically increasing the oxidation state and modulating the coordination environment of the Ir active sites anchored atop the NiFe oxyhydroxide layers. Based on the proposed mechanism, we have successfully anchored Ir single-atom sites on NiFe oxyhydroxides (Ir0.1/Ni9Fe SAC) via a unique in situ cryogenic–photochemical reduction method that delivers an overpotential of 183 mV at 10 mA ⋅ cm−2 and retains its performance following 100 h of operation in 1 M KOH electrolyte, outperforming the reported catalysts and the commercial IrO2 catalysts. These findings open the avenue toward an atomic-level understanding of the oxygen evolution of catalytic centers under in operando conditions.


2021 ◽  
Vol 60 (9) ◽  
pp. 6852-6852
Author(s):  
Md Asmaul Hoque ◽  
Abhishek Dutta Chowdhury ◽  
Somnath Maji ◽  
Jordi Benet-Buchholz ◽  
Mehmed Z. Ertem ◽  
...  

2021 ◽  
Vol 35 (3) ◽  
Author(s):  
Zohreh Shaghaghi ◽  
Parya Sallakh Kouhsangini ◽  
Rahim Mohammad‐Rezaei

Nanoscale ◽  
2021 ◽  
Author(s):  
Peng Wang ◽  
Feng Li ◽  
Xuefeng Long ◽  
Tong Wang ◽  
Huan Chai ◽  
...  

Surface modification by loading a water oxidation co-catalyst (WOC) is generally considered to be an efficient means to optimize the sluggish surface oxygen evolution reaction (OER) of hematite photoanode for...


2021 ◽  
pp. 149898
Author(s):  
Nguyen Duc Quang ◽  
Phuoc Cao Van ◽  
Duc Duy Le ◽  
Sutripto Majumder ◽  
Nguyen Duc Chinh ◽  
...  

2021 ◽  
Vol 119 (1) ◽  
pp. 013903
Author(s):  
Qian Yu ◽  
Minji Yang ◽  
Xin Luo ◽  
Zeyu Fan ◽  
Qianbao Wu ◽  
...  

Author(s):  
Tianqi Liu ◽  
Ge Li ◽  
Nannan Shen ◽  
Mårten S. G. Ahlquist ◽  
Licheng Sun

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