Valence Regulation of Ultrathin Cerium Vanadate Nanosheets for Enhanced Photocatalytic CO2 Reduction to CO

Atomic valence state regulation is an advantageous approach for improving photocatalytic efficiency and product selectivity. However, it is difficult to precisely control the ratio of the different valence states on the surface and the relationship between the surface valence change and catalytic efficiency in the photocatalytic reaction process is unclear. Herein, CeVO4 ultrathin nanosheets were fabricated by one-step solvothermal method with ethanolamine (MEA) as the structure-directing agent. The ratio of the concentrations of intrinsic Ce4+ and Ce3+ ions is precisely modulated from 19.82:100 to 13.33:100 changed by the volume of MEA added without morphology modification. The photocatalytic efficiency increases as the concentrations of intrinsic Ce4+ and Ce3+ ions decrease and CV3 (prepared with 3 mL of MEA) shows the highest CO generation rate approximately 6 and 14 times larger than CV (prepared without MEA) and CV1 (prepared with 1 mL of MEA), respectively, in the photocatalytic CO2 reduction. Interestingly, about 6.8% photo-induced Ce4+ ions were generated on the surface of the catalysts during the photocatalytic CO2 reduction without any phase and morphology changes for CV3. The photocatalytic reaction mechanism is proposed considering the intrinsic and photo-induced Ce4+ ions to obtain efficient photocatalysts.

Download Full-text

The three-dimensional flower-like Bi 2 WO 6 assisted by ethanolamine through a microwave method for efficient photocatalytic activity

Royal Society Open Science ◽

10.1098/rsos.181422 ◽

2019 ◽

Vol 6 (3) ◽

pp. 181422

Author(s):

Xingchen Liu ◽

SuZhen Wang ◽

Song Wang ◽

Han Shi ◽

Xiaolong Zhang ◽

...

Keyword(s):

Photocatalytic Activity ◽

Photoelectron Spectroscopy ◽

Three Dimensional ◽

Catalytic Performance ◽

Microwave Method ◽

Photocatalytic Efficiency ◽

X Ray Diffraction ◽

Structure Directing Agent ◽

X Ray ◽

One Step

The three-dimensional flower-like Bi 2 WO 6 was synthesized through a one-step microwave method (the reaction temperature was 434 K and the reaction took 10 min) with the assistance of ethanolamine (EA). The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, ultraviolet–visible spectroscopy, PL, X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller analysis. Methyl orange was used as target pollutant to evaluate the photocatalysis property of samples. Furthermore, the influence of the mechanism of EA on the structure and catalytic performance of Bi 2 WO 6 was discussed. The detailed characterizations revealed that the three-dimensional flower-like Bi 2 WO 6 was successfully synthesized with the assistance of EA. The results confirmed that EA significantly influenced the morphology of Bi 2 WO 6 products. The addition of EA can effectively alter the pressure of the reaction and improve the crystal phase and structure of Bi 2 WO 6 photocatalysts, enhancing the photocatalytic activity of samples and improving the photocatalytic efficiency. EA can serve as an assembling agent and structure-directing agent resulting in the formation of flower-like architectures. With the increase of the amount of EA, the as-prepared Bi 2 WO 6 sample gradually forms a flower-like structure, leading to a shorter time of light holes migrating to the surface of the catalyst. It makes the compound rate significantly decreased, and improves the photocatalytic efficiency of the sample.

Download Full-text

An experimental and theoretical study of the abrasion performance of digital light processing parts

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405420981333 ◽

2020 ◽

pp. 095440542098133

Author(s):

Mehdi Kazemi ◽

Abdolreza Rahimi

Keyword(s):

Layer Thickness ◽

Normal Load ◽

Digital Light Processing ◽

One Step ◽

Pin On Disk ◽

The Relationship ◽

Influential Parameters ◽

Disk Method ◽

Normal Angle

Generally, interactions at surface asperities are the cause of wear. Two-Thirds of wear in industry occurs because of the abrasive or adhesive mechanisms. This research presents an analytical model for abrasion of additive manufactured Digital Light Processing products using pin-on-disk method. Particularly, the relationship between abrasion volume, normal load, and surface asperities’ angle is investigated. To verify the proposed mathematical model, the results of this model are verified with the practical experiments. Results show that the most influential parameters on abrasion rate are normal load and surface’s normal angle. Abrasion value increases linearly with increasing normal load. The maximum abrasion value occurs when the surface’s normal angle during fabrication is 45°. After the asperities are worn the abrasion volume is the same for all specimens with different surface’s normal angle. Though layer thickness does not directly affect the wear rate, but surface roughness tests show that layer thickness has a great impact on the quality of the abraded surface. When the thickness of the layers is high, the abraded surface has deeper valleys, and thus has a more negative skewness. This paper presents an original approach in abrasion behavior improvement of DLP parts which no research has been done on it so far; thus, bringing the AM one step closer to maturity.

Download Full-text

CONCEPTUAL PROVISIONS ON THE DEVELOPMENT AND IMPLEMENTATION OF THE MECHANISM OF THE INSTITUTE OF TRUST FORMATION IN THE FINANCIAL SERVICES MARKET

SCIENTIFIC BULLETIN OF POLISSIA ◽

10.25140/2410-9576-2018-1-2(14)-8-15 ◽

2018 ◽

Vol 1 (2(14)) ◽

pp. 8-15

Author(s):

Serhiy Mykolaiovych Shkarlet ◽

Maksym Viktorovych Dubyna ◽

Olena Serhiivna Zhuk

Keyword(s):

Financial Services ◽

State Regulation ◽

Trust Building ◽

Mechanism Of Formation ◽

Target Setting ◽

Trust Formation ◽

New Ideas ◽

Methodological Principles ◽

The Relationship ◽

Further Development

Urgency of the research. In order to develop the financial services market, reform in this area needs to be implemented and measures should be taken to increase the level of trust among the key players in such a market. Target setting. The realities of Ukrainian system of state regulation of the financial intermediaries’ activity testify that the introduction of new ideas, concepts or provisions in this area requires the construction of an effective mechanism for their implementation. It should be clearly defined in the theoretical and methodological plane with the justification of its constituents. Actual scientific research and issues analysis. The works in the field of functioning of the financial services market should include the papers of such scientists: Bobrov Ye. A., Bondarenko Ye. P., Vyshyvana B. M., Voytenko O. M., Kovalenko Yu. M., Rekunenko І. І., Smagin V. L., Unets-Khodakivska V. P., Yuriya S. I., Yashchuk V. V., Asmundson I., Herring R., Stijn C., Wyman О. Uninvestigated parts of general matters defining. Despite the developments in this area, the theoretical and methodological principles of justification of the mechanism of forming confidence in the financial services market are not developed. The research objective. The purpose of the work is to develop the provisions for the creation and implementation of a mechanism for the establishment of a trust institution in the financial services market. The statement of basic materials. The importance of developing and implementing a mechanism of trust building in the financial services market for the further development of such a market is determined. The main elements of such a mechanism, the relationship between them are described and their essence and role in the process of building such a market are determined. Within the mechanism, its purpose, principles, functions, security units, methods and tools are identified. It is indicated that the mechanism should act in order to obtain concrete results, the types of which are defined. Conclusions. The article substantiates the principles of developing and implementing the mechanism of formation of the trust institution in the financial services market.

Download Full-text

Follower emotional intelligence

Personnel Review ◽

10.1108/pr-09-2017-0285 ◽

2019 ◽

Vol 48 (5) ◽

pp. 1239-1260

Author(s):

J. Irudhaya Rajesh ◽

Verma Prikshat ◽

Paul Shum ◽

L. Suganthi

Keyword(s):

Emotional Intelligence ◽

Structural Equation ◽

Theoretical Perspective ◽

Self Report ◽

Content Type ◽

Proposed Model ◽

One Step ◽

Cognitive Speed ◽

The Impact ◽

The Relationship

Purpose The purpose of this paper is to understand the impact of transformational leadership (TL) on follower emotional intelligence (EI) and examine the potential mediation role played by follower EI in the relationship between TL and follower outcomes (i.e. growth satisfaction in the job and job stress (JS)). Design/methodology/approach Data were obtained through survey using questionnaire collected from 908 employees who worked across six different sectors, i.e. manufacturing, IT, healthcare, hospitality, educational and public services in Southern India. The mediation model proposed in this study was tested using structural equation modelling and bootstrapping method. Findings The relationship between TL and Follower EI was significant. Follower EI was found to partially mediate the relationship between TL and followers’ growth satisfaction in job. Contrary to expectations, the follower EI did not significantly predict JS in this study and hence the follower EI did not mediate in the proposed model. However, follower EI and growth satisfaction in the job jointly mediated the relationship between TL and follower JS fully. Research limitations/implications Self-report bias about supervisors’ TL behaviours and followers’ own EI assessment and collection of data from the mono-source (subordinate self-report) might have impacted the results of this study. Moreover, some items were negatively worded and reverse coded as cognitive speed bumps to restrain the respondent’s tendency to rush through answering the survey questionnaire. Practical implications This study established a partial and joint mediation of follower EI on the relationship between TL and follower outcomes. Basing on these findings, this study highlights the need for the practitioners to better understand the importance of EI training for the leaders in the organisations for obtaining better outcomes in the followers. Social implications The study establishes the fact that the attunement of transformational leaders’ EI and follower EI help leaders as well as followers to guide their behaviour towards positive outcomes. Originality/value This study is among the first to examine the impact of TL on follower EI and the potential mediation of follower EI between TL and follower outcomes. From a theoretical perspective, this study is one step closer to fully understand the intervening process between TL and follower outcomes.

Download Full-text

Density functional theory (DFT) investigation on the structure and photocatalysis properties of double-perovskite Gd1−xCaxBaCo2O5+δ (0 ≤ x ≤ 0.4)

RSC Advances ◽

10.1039/c9ra02820j ◽

2019 ◽

Vol 9 (35) ◽

pp. 20161-20168

Author(s):

Rong Zhang ◽

Bo Xiang ◽

Lei Xu ◽

Liru Xia ◽

Chunhua Lu

Keyword(s):

Density Functional Theory ◽

Charge Transfer ◽

Density Functional ◽

Oxygen Vacancies ◽

Catalytic Efficiency ◽

Double Perovskite ◽

Functional Theory ◽

Ca Doping ◽

Valence States

Ca-doping affects the overall catalytic efficiency by adjusting the distribution of Co valence states and oxygen vacancies due to the strengthening of the charge transfer between O-2p and Co-3d orbitals upon substitution of Gd by Ca.

Download Full-text

A facile method to fabricate AC/CuO for efficient removal of organic pollutants by adsorption and persulfate-based advanced oxidation processes

Journal of Water Supply Research and Technology—AQUA ◽

10.2166/aqua.2020.094 ◽

2020 ◽

Author(s):

Youlin Li ◽

Yu Hu ◽

Wenqiao You ◽

Guangming Zhou ◽

Guilong Peng

Keyword(s):

Catalytic Performance ◽

Catalytic Degradation ◽

Maximum Adsorption Capacity ◽

Efficient Removal ◽

X Ray ◽

One Step ◽

Ft Ir ◽

Degradation Reaction ◽

The Relationship ◽

Insight Into

Abstract Activated carbon/CuO (AC/CuO) composites was prepared through a facile one-step hydrothermal method and used as a bifunctional material for adsorption and catalysis degradation of bisphenol A (BPA). The composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). The obtained AC/CuO exhibited excellent adsorption and catalytic performance. The maximum adsorption capacity of BPA on the AC/CuO was 319.03 mg/g according to the Langmuir fitting. At an initial BPA concentration of 20 mg/L, the BPA degradation efficiencies were maintained above 96% for 15 min by using 20 mg/L AC/CuO and 2 mM peroxymonosulfate (PMS). Moreover, the relationship between adsorption and catalytic degradation was also investigated. The results indicated that the pre-adsorption disfavored the degradation reaction. This work not only provides a novel preparation method for AC/CuO catalyst, but also gives a deeper insight into the mechanisms between adsorption and catalytic degradation.

Download Full-text

Analyzing the Relationship between Agricultural FDI and Food Security: Evidence from Belt and Road Countries

Sustainability ◽

10.3390/su12072906 ◽

2020 ◽

Vol 12 (7) ◽

pp. 2906

Author(s):

Hongxing Yao ◽

Mohammed Ismail Alhussam ◽

Omar Abu Risha ◽

Bilal Ahmed Memon

Keyword(s):

Food Security ◽

Direct Investment ◽

Direct Relationship ◽

Specific Effect ◽

Effect Model ◽

Belt And Road ◽

One Step ◽

Indirect Relationship ◽

Positive Direct ◽

The Relationship

This study analyzes the relationship between agricultural foreign direct investment (FDI) and food security on Belt and Road Initiative (BRI) countries in a panel framework over the period 2006–2015 using correlation analysis, the specific-effect model, and the 2SLS technique. The study aims to: first, analyze the correlation between agricultural FDI and food security for each country, individually; then, investigate whether there is a direct relationship, using the specific-effect model. Finally, by taking one step further, this study uses the 2SLS method to determine whether there is an indirect relationship through agricultural productivity. Our results show that the sampled countries have clear differences in the direction of the relationship between food security and agricultural FDI. But, in general, the agricultural FDI has a positive direct and indirect effect on food security; this effect is seen clearly when the country attracts agricultural FDIs steadily.

Download Full-text

Recent Advances and Applications of Semiconductor Photocatalytic Technology

Applied Sciences ◽

10.3390/app9122489 ◽

2019 ◽

Vol 9 (12) ◽

pp. 2489 ◽

Cited By ~ 28

Author(s):

Fubao Zhang ◽

Xianming Wang ◽

Haonan Liu ◽

Chunli Liu ◽

Yong Wan ◽

...

Keyword(s):

Photocatalytic Performance ◽

Low Cost ◽

Research Topic ◽

Living Standards ◽

Photocatalytic Reaction ◽

Large Specific Surface Area ◽

Photocatalytic Efficiency ◽

Comprehensive Information ◽

Full Utilization

Along with the development of industry and the improvement of people’s living standards, peoples’ demand on resources has greatly increased, causing energy crises and environmental pollution. In recent years, photocatalytic technology has shown great potential as a low-cost, environmentally-friendly, and sustainable technology, and it has become a hot research topic. However, current photocatalytic technology cannot meet industrial requirements. The biggest challenge in the industrialization of photocatalyst technology is the development of an ideal photocatalyst, which should possess four features, including a high photocatalytic efficiency, a large specific surface area, a full utilization of sunlight, and recyclability. In this review, starting from the photocatalytic reaction mechanism and the preparation of the photocatalyst, we review the classification of current photocatalysts and the methods for improving photocatalytic performance; we also further discuss the potential industrial usage of photocatalytic technology. This review also aims to provide basic and comprehensive information on the industrialization of photocatalysis technology.

Download Full-text

Geopolymer-TiO2 Nanocomposites for Photocsatalysis: Synthesis by One-Step Adding Treatment Versus Two-Step Acidification Calcination

Minerals ◽

10.3390/min9110658 ◽

2019 ◽

Vol 9 (11) ◽

pp. 658 ◽

Cited By ~ 2

Author(s):

Xiaohui Yang ◽

Yi Liu ◽

Chunjie Yan ◽

Ronghua Peng ◽

Hongquan Wang

Keyword(s):

Photocatalytic Activity ◽

Treatment Process ◽

Photocatalytic Efficiency ◽

Step Method ◽

Calcination Process ◽

Tio2 Particles ◽

Study Results ◽

Photocatalytic Activities ◽

One Step ◽

The One

Geopolymer-TiO2 nanocomposites were prepared by two different techniques, namely the two-step acidification calcination treatment and one-step adding method. The potential photocatalytic activities of geopolymer-TiO2 nanocomposites prepared by the two different methods were tested and compared. Nanocomposites prepared via the one-step process showed better photocatalytic activity. The amount of TiO2 particles loaded on the surface of the foaming materials was investigated by XRD and SEM-Mapping. By comparing with the sample obtained from two-step treatment, the TiO2 particles were distributed uniformly on the surface of the foaming materials for the sample obtained from the one-step method in this study. Results showed that the specific surface area of the geopolymer-TiO2 prepared by the one-step treatment process (28.67 m2/g) was significantly lower than the two-step acidification calcination process (215.04 m2/g), while the photocatalytic efficiency with methylene blue trihydrate (MB) was better. This is due to the more stable structure of geopolymer-TiO2 nanocomposites, the better dispersion and more loading of TiO2 particles on the foaming materials surfaces, leading to the enhanced photocatalytic activity.

Download Full-text

One-step coating of commercial Ni nanoparticles with a Ni, N-co-doped carbon shell towards efficient electrocatalysts for CO2 reduction

Chemical Communications ◽

10.1039/d0cc02188a ◽

2020 ◽

Vol 56 (54) ◽

pp. 7495-7498

Author(s):

Fangxin Mao ◽

Peng Fei Liu ◽

Pengfei Yang ◽

Jinlou Gu ◽

Hua Gui Yang

Keyword(s):

Nickel Nanoparticles ◽

Co2 Reduction ◽

Carbon Shell ◽

Ni Nanoparticles ◽

One Step ◽

Co Doped

Commercial nickel nanoparticles (Ni NPs) were directly converted to efficient electrocatalysts for CO2 reduction by urea–Ni solid powder pyrolysis, in which a Ni, N-co-doped graphite carbon shell wraps the Ni NPs in situ.

Download Full-text