scholarly journals Progress and Trend on the Regulation Methods for Nanozyme Activity and Its Application

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1057 ◽  
Author(s):  
Li Hou ◽  
Gaoyan Jiang ◽  
Ying Sun ◽  
Xuanhan Zhang ◽  
Juanjuan Huang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Cost ◽  
Catalytic Efficiency ◽  
Research Process ◽  
Research Progress ◽  
Practical Applications ◽  
High Purification ◽  
Natural Enzyme ◽  
Application Fields ◽  
Made In

Natural enzymes, such as biocatalysts, are widely used in biosensors, medicine and health, the environmental field, and other fields. However, it is easy for natural enzymes to lose catalytic activity due to their intrinsic shortcomings including a high purification cost, insufficient stability, and difficulties of recycling, which limit their practical applications. The unexpected discovery of the Fe3O4 nanozyme in 2007 has given rise to tremendous efforts for developing natural enzyme substitutes. Nanozymes, which are nanomaterials with enzyme-mimetic catalytic activity, can serve as ideal candidates for artificial mimic enzymes. Nanozymes possess superiorities due to their low cost, high stability, and easy preparation. Although great progress has been made in the development of nanozymes, the catalytic efficiency of existing nanozymes is relatively low compared with natural enzymes. It is still a challenging task to develop nanozymes with a precise regulation of catalytic activity. This review summarizes the classification and various strategies for modulating the activity as well as research progress in the different application fields of nanozymes. Typical examples of the recent research process of nanozymes will be presented and critically discussed.

Tuning the Edge-Site Activity of 2H Phase MoSe2 for Hydrogen Evolution Reaction via Sulfur Substitution and Strain Engineering

2020 ◽  
Vol 12 (10) ◽  
pp. 1446-1456
Author(s):  
Ziwei Xu ◽  
Guanghui Zhao ◽  
Mingyuan Wang ◽  
Jingjing Liang ◽  
Shahid Hussain ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
High Efficiency ◽  
Low Cost ◽  
Catalytic Efficiency ◽  
Strain Engineering ◽  
Catalyst Design ◽  
Potential Candidate

The 2H phase MoSe2 of high chemical stability and excellent catalytic activity is a promising catalyst for the hydrogen evolution reaction (HER) as a potential candidate, due to its low cost, high efficiency and abundant production. However, the HER catalytic efficiency of MoSe2 largely depends on the activity of reaction sites including the basal plane and the edges, and remains low because only the Mo edge sites are active. Herein, we have calculated the structural stability, catalytic activity, and strain engineering on sulfur substituted MoSe2 catalytic structures (Mo(Se1–xSx)2) by density functional theory. The results demonstrate that most of Mo(Se1–xSx)2 monolayers are thermodynamically stable and the HER activity of the Mo(Se1–xSx)2 monolayers can be effectively tuned by both element substitution and strain engineering with the mechanisms uncovered at the atomic level. This study provides the experiments theoretical references for the novel catalyst design of the hydrogen evolution reaction.

scholarly journals Designer bioemulsifiers based on combinations of different polysaccharides with the novel emulsifying esterase AXE from Bacillus subtilis CICC 20034

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Weiyi Tao ◽  
Junzhang Lin ◽  
Weidong Wang ◽  
He Huang ◽  
Shuang Li
Keyword(s):  
Low Cost ◽  
The Novel ◽  
Emulsifying Activity ◽  
Practical Applications ◽  
High Purification ◽  
Potential Benefits ◽  
Application Potential ◽  
Low Toxicity ◽  
Acidic Conditions ◽  
Surface Active Compounds

Abstract Background Bioemulsifiers are surface-active compounds, which exhibit advantages including low toxicity, higher biodegradability and biocompatibility over synthetic chemical surfactants. Despite their potential benefits, some obstacles impede the practical applications of bioemulsifiers, including low yields and high purification costs. Here, we aimed to exploit a novel protein bioemulsifier with efficient emulsifying activity and low-production cost, as well as proposed a design-bioemulsifier system that meets different requirements of industrial emulsification in the most economical way. Results The esterase AXE was first reported for its efficient emulsifying activity and had been studied for possible application as a protein bioemulsifier. AXE showed an excellent emulsification effect with different hydrophobic substrates, especially short-chain aliphatic and benzene derivatives, as well as excellent stability under extreme conditions such as high temperature (85 °C) and acidic conditions. AXE also exhibited good stability over a range of NaCl, MgSO4, and CaCl2 concentrations from 0 to 1000 mM, and the emulsifying activity even showed a slight increase at salt concentrations over 500 mM. A design-bioemulsifier system was proposed that uses AXE in combination with a variety of polysaccharides to form efficient bioemulsifier, which enhanced the emulsifying activity and further lowered the concentration of AXE needed in the complex. Conclusions AXE showed a great application potential as a novel bioemulsifier with excellent emulsifying ability. The AXE-based-designer bioemulsifier could be obtained in the most economical way and open broad new fields for low-cost, environmentally friendly bioemulsifiers.

scholarly journals Cu0.4Co0.6MoO4 Nanorods Supported on Graphitic Carbon Nitride as a Highly Active Catalyst for the Hydrolytic Dehydrogenation of Ammonia Borane

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 714 ◽  
Author(s):  
Junhao Li ◽  
Fangyuan Li ◽  
Jinyun Liao ◽  
Quanbing Liu ◽  
Hao Li
Keyword(s):  
Catalytic Activity ◽  
Carbon Nitride ◽  
Low Cost ◽  
Ammonia Borane ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
High Catalytic Activity ◽  
High Hydrogen ◽  
Practical Applications ◽  
Highly Active

As a typical chemical hydride, ammonia borane (AB) has received extensive attention because of its safety and high hydrogen storage capacity. The aim of this work was to develop a cost-efficient and highly reactive catalyst for hydrolyzing AB. Herein, we synthesized a series of CuxCo1–xMoO4 dispersed on graphitic carbon nitride (g-C3N4) to dehydrogenate AB. Among those CuxCo1–xMoO4/g-C3N4 catalysts, Cu0.4Co0.6MoO4/g-C3N4 exhibited the highest site time yield (STY) value of 75.7 m o l H 2 m o l c a t − 1   m i n − 1 with a low activation energy of 14.46 kJ mol−1. The STY value for Cu0.4Co0.6MoO4/g-C3N4 was about 4.3 times as high as that for the unsupported Cu0.4Co0.6MoO4, indicating that the g-C3N4 support plays a crucial role in improving the catalytic activity. Considering its low cost and high catalytic activity, our Cu0.4Co0.6MoO4/g-C3N4 catalyst is a strong candidate for AB hydrolysis for hydrogen production in practical applications.

Programmable Integrated Photonics

2020 ◽  
Author(s):  
José Capmany ◽  
Daniel Pérez
Keyword(s):  
Integrated Circuit ◽  
Performance Monitoring ◽  
Low Cost ◽  
Limiting Factors ◽  
External Control ◽  
Integrated Photonics ◽  
New Paradigm ◽  
Photonic Integrated Circuit ◽  
And Performance ◽  
Application Fields

Programmable Integrated Photonics (PIP) is a new paradigm that aims at designing common integrated optical hardware configurations, which by suitable programming can implement a variety of functionalities that, in turn, can be exploited as basic operations in many application fields. Programmability enables by means of external control signals both chip reconfiguration for multifunction operation as well as chip stabilization against non-ideal operation due to fluctuations in environmental conditions and fabrication errors. Programming also allows activating parts of the chip, which are not essential for the implementation of a given functionality but can be of help in reducing noise levels through the diversion of undesired reflections. After some years where the Application Specific Photonic Integrated Circuit (ASPIC) paradigm has completely dominated the field of integrated optics, there is an increasing interest in PIP justified by the surge of a number of emerging applications that are and will be calling for true flexibility, reconfigurability as well as low-cost, compact and low-power consuming devices. This book aims to provide a comprehensive introduction to this emergent field covering aspects that range from the basic aspects of technologies and building photonic component blocks to the design alternatives and principles of complex programmable photonics circuits, their limiting factors, techniques for characterization and performance monitoring/control and their salient applications both in the classical as well as in the quantum information fields. The book concentrates and focuses mainly on the distinctive features of programmable photonics as compared to more traditional ASPIC approaches.

scholarly journals Chemical Modification of Combusted Coal Gangue for U(VI) Adsorption: Towards a Waste Control by Waste Strategy

2021 ◽  
Vol 13 (15) ◽  
pp. 8421
Author(s):  
Yuan Gao ◽  
Jiandong Huang ◽  
Meng Li ◽  
Zhongran Dai ◽  
Rongli Jiang ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Efficiency ◽  
Low Cost ◽  
Chemical Activation ◽  
Cost Effective ◽  
Coal Gangue ◽  
Order Kinetic ◽  
Practical Applications ◽  
Detailed Structural Analysis ◽  
Alkaline Conditions

Uranium mining waste causes serious radiation-related health and environmental problems. This has encouraged efforts toward U(VI) removal with low cost and high efficiency. Typical uranium adsorbents, such as polymers, geopolymers, zeolites, and MOFs, and their associated high costs limit their practical applications. In this regard, this work found that the natural combusted coal gangue (CCG) could be a potential precursor of cheap sorbents to eliminate U(VI). The removal efficiency was modulated by chemical activation under acid and alkaline conditions, obtaining HCG (CCG activated with HCl) and KCG (CCG activated with KOH), respectively. The detailed structural analysis uncovered that those natural mineral substances, including quartz and kaolinite, were the main components in CCG and HCG. One of the key findings was that kalsilite formed in KCG under a mild synthetic condition can conspicuous enhance the affinity towards U(VI). The best equilibrium adsorption capacity with KCG was observed to be 140 mg/g under pH 6 within 120 min, following a pseudo-second-order kinetic model. To understand the improved adsorption performance, an adsorption mechanism was proposed by evaluating the pH of uranyl solutions, adsorbent dosage, as well as contact time. Combining with the structural analysis, this revealed that the uranyl adsorption process was mainly governed by chemisorption. This study gave rise to a utilization approach for CCG to obtain cost-effective adsorbents and paved a novel way towards eliminating uranium by a waste control by waste strategy.

scholarly journals Preparation and photocatalytic performance of metallic Nb0.9Ta0.1S2/2D-C3N4 composite

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Hanxiang Chen ◽  
Jianjian Yi ◽  
Zhao Mo ◽  
Yanhua Song ◽  
Wenshu Yang ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Low Cost ◽  
Metal Sulfide ◽  
Electron Hole ◽  
Practical Applications ◽  
Energy And Environment ◽  
Photocatalytic Application ◽  
Light Utilization ◽  
Ternary Metal ◽  
Key Issues

Abstract Photocatalysis technology has potential application in the field of energy and environment. How to expand visible light utilization and promote the separation efficiency of the carriers are the key issues for the high active photocatalysts preparation and future practical applications. In this work, a ternary metal sulfide Nb0.9Ta0.1S2 was prepared and used as an electron collector in the photocatalytic application. As a result, the generated electrons are quickly transferred to the surface of the composite to participate in the reaction. It was demonstrated that the photocatalytic activity of 2D-C3N4 was enhanced after the modification of Nb0.9Ta0.1S2. The Nb0.9Ta0.1S2/2D-C3N4 composite material was synthesized by solvothermal method. The composition of 5% Nb0.9Ta0.1S2/2D-C3N4 showed the highest H2 evolution rate of 1961.6 μmolg−1h−1, which was 6.6 times that of 2D-C3N4. The 15% Nb0.9Ta0.1S2/2D-C3N4 exhibited the best activity in Rhodamine B degradation rate of 97% in 2 h, which is 50% higher than that of 2D-C3N4. Nb0.9Ta0.1S2/2D-C3N4 can be used as electron trap to promote the effective separation of electron–hole pairs. This work provides benchmarks in exploring low-cost and efficient cocatalyst.

scholarly journals A Survey on Deep Learning Based Methods and Datasets for Monocular 3D Object Detection

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 517
Author(s):  
Seong-heum Kim ◽  
Youngbae Hwang
Keyword(s):  
Deep Learning ◽  
Object Detection ◽  
Low Cost ◽  
Detection Methods ◽  
Future Research ◽  
3D Object ◽  
Practical Applications ◽  
Depth Sensors ◽  
Significant Research ◽  
3D Object Detection

Owing to recent advancements in deep learning methods and relevant databases, it is becoming increasingly easier to recognize 3D objects using only RGB images from single viewpoints. This study investigates the major breakthroughs and current progress in deep learning-based monocular 3D object detection. For relatively low-cost data acquisition systems without depth sensors or cameras at multiple viewpoints, we first consider existing databases with 2D RGB photos and their relevant attributes. Based on this simple sensor modality for practical applications, deep learning-based monocular 3D object detection methods that overcome significant research challenges are categorized and summarized. We present the key concepts and detailed descriptions of representative single-stage and multiple-stage detection solutions. In addition, we discuss the effectiveness of the detection models on their baseline benchmarks. Finally, we explore several directions for future research on monocular 3D object detection.

Ni-P Amorphous Alloy Efficient Electrocatalyst with Hierarchical Structure toward Borohydride Oxidation

2021 ◽  
Author(s):  
Jingjing Yu ◽  
Bihao Hu ◽  
Chuanlan Xu ◽  
Jiazhi Meng ◽  
Shu Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Amorphous Alloy ◽  
Hierarchical Structure ◽  
Low Cost ◽  
Practical Application ◽  
Borohydride Oxidation

Nickel is widely researched in the electrooxidation of borohydride due to its low cost and abundant reserves, but it’s catalytic activity and stability need to be improved for practical application....

scholarly journals Towards a Transdisciplinary Theoretical Framework of Citizen Science: Results from a Meta-Review Analysis

2021 ◽  
Vol 13 (14) ◽  
pp. 7904
Author(s):  
Andrea Spasiano ◽  
Salvatore Grimaldi ◽  
Alessio Maria Braccini ◽  
Fernando Nardi
Keyword(s):  
Citizen Science ◽  
Information Technologies ◽  
Research Process ◽  
Theoretical Framework ◽  
Organizational Studies ◽  
Digital Platforms ◽  
Social Challenges ◽  
Review Analysis ◽  
Meta Review ◽  
Application Fields

This work intends to lay the foundations for a theoretical framework of citizen science combining social and organizational implications with the support of information technologies. The proposed theoretical framework moves towards a shared and common research process between experts and citizens to deal with environmental and social challenges. The role and capacity of online communities is explored and their engagement capacity by means of web-based digital platforms supporting crowdsourcing activities. In this contribution, authors highlight the most common practices, methods and issues of citizen science approaches adopted from multidisciplinary application fields to obtain insights for designing a new participative approach for organizational studies. To reach this goal, authors illustrate the results of a systematic meta-review analysis, consisting of an accurate selection and revision of journal review articles in order to highlight concepts, methods, research design approaches and tools adopted in citizen science approaches.

scholarly journals Bimetallic Ni-Based Catalysts for CO2 Methanation: A Review

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula
Keyword(s):  
Low Temperature ◽  
Noble Metals ◽  
Recent Progress ◽  
Low Cost ◽  
Alloy Formation ◽  
Co2 Methanation ◽  
High Performing ◽  
Mobile Sources ◽  
Low Dispersion ◽  
Made In

CO2 methanation has recently emerged as a process that targets the reduction in anthropogenic CO2 emissions, via the conversion of CO2 captured from point and mobile sources, as well as H2 produced from renewables into CH4. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO2 methanation reaction.

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