scholarly journals 3D Urchin-Like CuO Modified W18O49 Nanostructures for Promoted Photocatalytic Hydrogen Evolution under Visible Light Irradiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
Hongyu Ma ◽  
Yaqi Tan ◽  
Zhifei Liu ◽  
Jianhong Wei ◽  
Rui Xiong

Photocatalytic hydrogen evolution is a promising “green chemistry” route driven by sunlight for the direct water splitting into value-added hydrogen energy. Herein, with the object of exploring the effect of CuO loading on W18O49 photocatalytic activity, a 3D Urchin-like CuO modified W18O49 (CuO/W18O49) microspheres with different CuO loadings were synthesized via thermochemical precipitation combined with solvent-thermal method. The obtained CuO/W18O49 microspheres were analyzed by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL), etc. The results infer that the urchin-like 3D morphology with a high surface area and abundant 1D nanowires promotes electron transfer, the introduction of CuO further increases the number of active sites, thereby ensuring fast interfacial charge transfer to improve photocatalytic performance. During photocatalytic H2 evolution from water splitting, 5 wt.% CuO/W18O49 shows the optimal performance, the H2 yield is almost 3.22 times that of the undoped counterparts. This work presents that oxygen-vacancy-rich heterojunction nanocomposites can be used as a new strategy to design materials with high photocatalytic activity.

2013 ◽  
Vol 724-725 ◽  
pp. 740-743
Author(s):  
Shi Zhao Kang ◽  
Tan Wu ◽  
Xiang Qing Li ◽  
Qi Fan Wang ◽  
Jin Mu

CuO-decorated core-shell montmorillonite-TiO2 colloids were prepared and characterized with transmission electron microscope, powder X-ray diffraction analysis, Brunauer-Emmett-Teller analysis and UV-vis spectrua. Meanwhile, their photocatalytic activity for hydrogen evolution from water was explored under UV irradiation using methanol as a sacrificial reagent. The results indicate that they are an efficient photocatalyst with a rate of H2 evolution of 219 μmol·h-1·g-1 which is higher than that of anatase TiO2 nanoparticles.


2006 ◽  
Vol 974 ◽  
Author(s):  
Jaturong Jitputti ◽  
Sorapong Pavasupree ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa

ABSTRACTTantalate and titanate photocatalysts were prepared by solid-state reaction at 1273 K using various ratios of SrCO3, Ta2O5, and TiO2 as starting materials. The prepared solid photocatalysts were characterized using XRD and SEM analysis. These prepared tantalate and titanate photocatalysts showed high photocatalytic H2 evolution activity by water splitting without co-catalyst loading. The highest H2 evolution rate of prepared photocatalysts was found to be 138 μmolh−1 with the starting materials ratio of 2/0.5/1.5 (Sr/Ta/Ti; mol). Furthermore, this photocatalyst showed photocatalytic activity for H2 evolution from distilled water.


2018 ◽  
Vol 54 (47) ◽  
pp. 5943-5955 ◽  
Author(s):  
Bo You ◽  
Guanqun Han ◽  
Yujie Sun

We have summarized the recent progress in electrocatalytic and photocatalytic water splitting integrated with organic oxidation for efficient H2 generation, which features no formation of explosive H2/O2 mixtures and reactive oxygen species, higher efficiency compared to conventional water splitting and potential co-production of value-added organic products.


Author(s):  
Sichen Wei ◽  
Soojung Baek ◽  
Hongyan Yue ◽  
Maomao Liu ◽  
Seok Joon Yun ◽  
...  

Abstract The development of active catalysts for hydrogen evolution reaction (HER) made from low-cost materials constitutes a crucial challenge in the utilization of hydrogen energy. Earth-abundant molybdenum disulfide (MoS2) has been discovered recently with good activity and stability for HER. In this report, we employ a hydrothermal technique for MoS2 synthesis which is a cost-effective and environmentally friendly approach and has the potential for future mass production. Machine-learning (ML) techniques are built and subsequently used within a Bayesian Optimization framework to validate the optimal parameter combinations for synthesizing high-quality MoS2 catalyst within the limited parameter space. Compared with the heavy-labor and time-consuming trial-and-error approach, the ML techniques provide a more efficient toolkit to assist exploration of the most effective HER catalyst in hydrothermal synthesis. To investigate the structure-property relationship, scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and various electrochemical characterizations have been conducted to investigate the superiority of the ML validated optimized sample. A strong correlation between the material structure and the HER performance has been observed for the optimized MoS2 catalyst.


CrystEngComm ◽  
2021 ◽  
Vol 23 (13) ◽  
pp. 2547-2555
Author(s):  
Ting Feng ◽  
Kaili Zhao ◽  
Haiyan Li ◽  
Wei Wang ◽  
Bohua Dong ◽  
...  

2D/2D MoSe2/ZnIn2S4 heterojunctions exhibit high photocatalytic activity owing to MoSe2 as a cocatalyst, which provides more active sites, reducing the overpotential and the activation energy for water reduction.


2020 ◽  
Vol 16 ◽  
Author(s):  
Yuxue Wei ◽  
Honglin Qin ◽  
Jinxin Deng ◽  
Xiaomeng Cheng ◽  
Mengdie Cai ◽  
...  

Introduction: Solar-driven photocatalytic hydrogen production from water splitting is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. In this review, recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. In particular, the factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Background: Photocatalytic hydrogen evolution from water splitting using photocatalyst semiconductors is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. Methods: This review summarizes the recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation. Results: Recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. The factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Conclusion: The state-of-the-art CdS for producing hydrogen from photocatalytic water splitting under visible light is discussed. The future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are also described.


2021 ◽  
Vol 45 (1) ◽  
pp. 162-168
Author(s):  
Tao Li ◽  
Jiandong Cui ◽  
Yezhan Lin ◽  
Kecheng Liu ◽  
Rui Li ◽  
...  

The enhanced photocatalytic hydrogen evolution performance of g-C3N4–Co3O4 2D–1D Z-scheme heterojunctions was achieved through the synergistic effect of the cobalt ion redox, conductive polyaniline, and a Co3O4 nanobelt.


Author(s):  
Adem Sarilmaz ◽  
Eminegul Genc ◽  
Emre Aslan ◽  
Abdurrahman Ozen ◽  
Gizem Yanalak ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.


2021 ◽  
Author(s):  
Xunliang Hu ◽  
Irshad Hussain ◽  
Bien Tan

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.


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