Showing papers by "Southwest University of Science and Technology published in 2019"
TL;DR: In this article, the authors summarize the emerging attractive characteristics of stationary NIBs, such as high-rate capability, all-climate operation, and full-battery recyclability.
Abstract: Owing to the excellent abundance and availability of sodium reserves, sodium ion batteries (NIBs) show great promise for meeting the material supply and cost demands of large-scale energy storage systems (ESSs) used for the application of renewable energy sources and smart grids. However, the cost advantages of stationary NIBs alone are not enough to ensure their commercial success. In this review, we summarize the emerging attractive characteristics of stationary NIBs, such as high-rate capability, all-climate operation, and full-battery recyclability. Together with inherent cost advantages, these merits have resulted in an excellent compatibility between stationary NIBs and large-scale ESSs that dictates their validity in practical applications. Representative electrode materials are highlighted to illustrate advances in corresponding features. The insights presented in this review can inspire further research interest into NIB design and serve as a guide for the application of NIBs in large-scale stationary energy storage.
351 citations
TL;DR: In this article, the authors give a comprehensive introduction about the recent developments in engineering g-C3N4 by constructing heterostructures or diverse morphologies to improve its photodegradation performance for the photocatalytic degradation of persistent organic pollutants.
328 citations
TL;DR: An atomically dispersed Ru1-N4 site anchored on nitrogen-carbon support (Ru-N-C) is reported as an efficient and durable electrocatalyst for acidic OER.
Abstract: Achieving active and stable oxygen evolution reaction (OER) in acid media based on single-atom catalysts is highly promising for cost-effective and sustainable energy supply in proton electrolyte membrane electrolyzers. Here, we report an atomically dispersed Ru1-N4 site anchored on nitrogen-carbon support (Ru-N-C) as an efficient and durable electrocatalyst for acidic OER. The single-atom Ru-N-C catalyst delivers an exceptionally intrinsic activity, reaching a mass activity as high as 3571 A gmetal−1 and turnover frequency of 3348 O2 h−1 with a low overpotential of 267 mV at a current density of 10 mA cm−2. The catalyst shows no evident deactivation or decomposition after 30-hour operation in acidic environment. Operando synchrotron radiation X-ray absorption spectroscopy and infrared spectroscopy identify the dynamic adsorption of single oxygen atom on Ru site under working potentials, and theoretical calculations demonstrate that the O-Ru1-N4 site is responsible for the high OER activity and stability. Monitoring catalyst structural changes under working conditions is crucial for understanding how catalysts operate. Here, authors examine single-atom Ru electrocatalyst by operando synchrotron spectroscopies to identify the catalytic mechanism during the acidic oxygen evolution reaction.
324 citations
TL;DR: This review summarized the advances of weed detection using ground-based machine vision and image processing techniques and application of conventional machine learning-based and recently developed deep learning- based approaches for weed detection were presented.
321 citations
TL;DR: It is reported that the Mo2C nanorod serves as an excellent NRR electrocatalyst for artificial N2 fixation to NH3 with strong durability and acceptable selectivity under ambient conditions.
Abstract: The synthesis of NH3 is mainly dominated by the traditional energy-consuming Haber–Bosch process with a mass of CO2 emission. Electrochemical conversion of N2 to NH3 emerges as a carbon-free process for the sustainable artificial N2 reduction reaction (NRR), but requires an efficient and stable electrocatalyst. Here, we report that the Mo2C nanorod serves as an excellent NRR electrocatalyst for artificial N2 fixation to NH3 with strong durability and acceptable selectivity under ambient conditions. Such a catalyst shows a high Faradaic efficiency of 8.13% and NH3 yield of 95.1 μg h–1 mg–1cat at −0.3 V in 0.1 M HCl, surpassing the majority of reported electrochemical conversion NRR catalysts. Density functional theory calculation was carried out to gain further insight into the catalytic mechanism involved.
271 citations
TL;DR: It is found that NH3 emission abatement can mitigate PM2.5 pollution and nitrogen deposition but would worsen acid rain in China, and a region-specific strategy for multipollutant controls that will benefit human and ecosystem health is proposed.
Abstract: China has been experiencing fine particle (i.e., aerodynamic diameters ≤ 2.5 µm; PM2.5) pollution and acid rain in recent decades, which exert adverse impacts on human health and the ecosystem. Recently, ammonia (i.e., NH3) emission reduction has been proposed as a strategic option to mitigate haze pollution. However, atmospheric NH3 is also closely bound to nitrogen deposition and acid rain, and comprehensive impacts of NH3 emission control are still poorly understood in China. In this study, by integrating a chemical transport model with a high-resolution NH3 emission inventory, we find that NH3 emission abatement can mitigate PM2.5 pollution and nitrogen deposition but would worsen acid rain in China. Quantitatively, a 50% reduction in NH3 emissions achievable by improving agricultural management, along with a targeted emission reduction (15%) for sulfur dioxide and nitrogen oxides, can alleviate PM2.5 pollution by 11-17% primarily by suppressing ammonium nitrate formation. Meanwhile, nitrogen deposition is estimated to decrease by 34%, with the area exceeding the critical load shrinking from 17% to 9% of China's terrestrial land. Nevertheless, this NH3 reduction would significantly aggravate precipitation acidification, with a decrease of as much as 1.0 unit in rainfall pH and a corresponding substantial increase in areas with heavy acid rain. An economic evaluation demonstrates that the worsened acid rain would partly offset the total economic benefit from improved air quality and less nitrogen deposition. After considering the costs of abatement options, we propose a region-specific strategy for multipollutant controls that will benefit human and ecosystem health.
264 citations
TL;DR: In this article, a review mainly summarized the recent studies for the synthesis, fabrication and surface modification of novel nanomaterials and their applications in the efficient elimination and solidification of radionuclides, and discussed the interaction mechanisms from batch experiments, spectroscopy analysis and theoretical calculations.
Abstract: With the development of nuclear energy, large amounts of radionuclides are inevitably released into the natural environment. It is necessary to eliminate radionuclides from wastewater for the protection of environment. Nanomaterials have been considered as the potential candidates for the effective and selective removal of radionuclides from aqueous solutions under complicated conditions because of their high specific surface area, large amounts of binding sites, abundant functional groups, pore-size controllable and easily surface modification. This review mainly summarized the recent studies for the synthesis, fabrication and surface modification of novel nanomaterials and their applications in the efficient elimination and solidification of radionuclides, and discussed the interaction mechanisms from batch experiments, spectroscopy analysis and theoretical calculations. The sorption capacities with other materials, advantages and disadvantages of different nanomaterials are compared, and at last the perspective of the novel nanomaterials is summarized.
246 citations
TL;DR: In this article, boron nanosheet (BNS) is proposed as an elemental two-dimensional (2D) material to effectively catalyze the N2 reduction reaction toward NH3 synthesis with excellent selectivity.
Abstract: The Haber–Bosch process for industrial NH3 production suffers from harsh reaction conditions and serious CO2 emission. Electrochemical N2 reduction offers a carbon-neutral alternative for more energy-saving NH3 synthesis but requires active electrocatalysts for the N2 reduction reaction (NRR). In this Letter, boron nanosheet (BNS) is proposed as an elemental two-dimensional (2D) material to effectively catalyze the NRR toward NH3 synthesis with excellent selectivity. When tested in 0.1 M Na2SO4, such BNS catalyst attains a high Faradaic efficiency of 4.04% and a large NH3 yield of 13.22 μg h–1 mgcat–1 at −0.80 V vs reversible hydrogen electrode, with strong electrochemical durability. Density functional theory calculations suggest that the B atoms of both oxidized and H-deactivated BNS can catalyze the NRR more effectively than clean BNS, and the rate-determining step is the desorption process of the second NH3 gas.
236 citations
TL;DR: This review provides a distinct perspective of the history, present, and future of OER electrocatalysts at mild conditions and concludes with a brief outlook on the possible remaining challenges and future trends of neutral or near-neutral OER electrodes.
Abstract: Developing anodic oxygen evolution reaction (OER) electrocatalysts with high catalytic activities is of great importance for effective water splitting. Compared with the water-oxidation electrocatalysts that are commonly utilized in alkaline conditions, the ones operating efficiently under neutral or near neutral conditions are more environmentally friendly with less corrosion issues. This review starts with a brief introduction of OER, the importance of OER in mild-pH media, as well as the fundamentals and performance parameters of OER electrocatalysts. Then, recent progress of the rational design of electrocatalysts for OER in mild-pH conditions is discussed. The chemical structures or components, synthetic approaches, and catalytic performances of the OER catalysts will be reviewed. Some interesting insights into the catalytic mechanism are also included and discussed. It concludes with a brief outlook on the possible remaining challenges and future trends of neutral or near-neutral OER electrocatalysts. It hopefully provides the readers with a distinct perspective of the history, present, and future of OER electrocatalysts at mild conditions.
231 citations
TL;DR: In this article, the authors evaluated the potential of a new machine learning algorithm using gradient boosting on decision trees with categorical features support (i.e., CatBoost) for accurately estimating daily ET0 with limited meteorological data in humid regions of China.
229 citations
TL;DR: In this paper, the authors investigated the absorption mechanism of microwave absorbents with ultrathin thickness and ultralow density and found that moderate dielectric loss, magnetic loss, good impedance matching and porous structure contributed to high microwave absorption.
Abstract: Ultrathin thickness ( 3.5 GHz. The investigation of the absorption mechanism revealed that moderate dielectric loss, magnetic loss, good impedance matching and the porous structure contributed to the high microwave absorption. This work opens up a potential strategy to prepare excellent microwave absorbents with ultrathin thickness and ultralow density.
TL;DR: A novel fractional grey model called the fractional time delayed grey model, which significantly outperforms the other 8 existing grey models is proposed and applied to forecast the coal and natural gas consumption of Chongqing China.
TL;DR: A novel nonlinear grey Bernoulli model with fractional order accumulation, abbreviated as FANGBM(1,1) model, is proposed to forecast short-term renewable energy consumption of China during the 13th Five-Year Plan (2016–2020).
TL;DR: In this article, a disulfide-containing carboxylic acid is applied as a curing agent to synthesize epoxy vitrimers with simultaneous Disulfide metathesis and carboxylate transesterification.
Abstract: Vitrimers make up a class of polymeric materials combining the advantages of thermosets and thermoplastics, because they can be reprocessed while being at the same time permanently cross-linked. However, a long heating duration or an elevated temperature is necessary for most vitrimers to relax the stress from deformation and exhibit malleability. Herein, a disulfide-containing carboxylic acid is applied as a curing agent to synthesize epoxy vitrimers with simultaneous disulfide metathesis and carboxylate transesterification. The insoluble networks exhibit rapid stress relaxation and have relaxation times ranging from 1.5 s (200 °C) to 5500 s (60 °C), while the temperature of malleability is as low as 65 °C. Moreover, this vitrimer can be efficiently reprocessed at 100 °C in 1 h with full recovery of mechanical strength for at least four cycles. Additionally, such a material is simply synthesized from commercially available chemicals and may have potential applications in the electronics industry where a ...
TL;DR: Jingrun Ran, Jiangtao Qu, Hongping Zhang, Tian Wen, Hailong Wang, Shuangming Chen, Li Song, Xuliang Zhang, Liqiang Jing, Rongkun Zheng, Shi‐Zhang Qiao as discussed by the authors
Abstract: Jingrun Ran, Jiangtao Qu, Hongping Zhang, Tian Wen, Hailong Wang, Shuangming Chen, Li Song, Xuliang Zhang, Liqiang Jing, Rongkun Zheng, Shi‐Zhang Qiao
TL;DR: Surface potential change measurement and liquid photoluminescence decay spectra confirm that the atomically ultrathin structure can shorten the transfer distance of charge carriers from the interior onto the surface and decrease the recombination in body, which is beneficial for activation and reduction of CO2.
Abstract: Atomically thin, single-crystalline InVO4 sheets with the uniform thickness of ∼1.5 nm were convincingly synthesized, which was identified with strong, low-angle X-ray diffraction peaks. The InVO4 atomic layer corresponding to 3 unit cells along [110] orientation exhibits highly selective and efficient photocatalytic conversion of CO2 into CO in the presence of water vapor. Surface potential change measurement and liquid photoluminescence decay spectra confirm that the atomically ultrathin structure can shorten the transfer distance of charge carriers from the interior onto the surface and decrease the recombination in body. It thus allows more electrons to survive and accumulate on the surface, which is beneficial for activation and reduction of CO2. In addition, exclusively exposed {110} facet of the InVO4 atomic layer was found to bind the generating CO weakly, facilitating quick desorption from the catalyst surface to form free CO molecules, which provides an ideal platform to catalytically selective ...
TL;DR: Wang et al. as mentioned in this paper investigated the factors that can mitigate carbon-dioxide (CO2) intensity and further assessed CMRBS in China based on a household scale via decomposition analysis.
TL;DR: Decontamination experiments confirm that SCU-102 represents the optimal Tc scavenger with the highest reported clean-up efficiency, while first-principle simulations reveal that the origin of the selectivity is the recognition of TcO4 - by the hydrophobic pockets of the structure.
Abstract: 99 Tc contamination at legacy nuclear sites is a serious and unsolved environmental issue. The selective remediation of 99 TcO4 - in the presence of a large excess of NO3 - and SO4 2- from natural waste systems represents a significant scientific and technical challenge, since anions with a higher charge density are often preferentially sorbed by traditional anion-exchange materials. We present a solution to this challenge based on a stable cationic metal-organic framework, SCU-102 (Ni2 (tipm)3 (NO3 )4 ), which exhibits fast sorption kinetics, a large capacity (291 mg g-1 ), a high distribution coefficient, and, most importantly, a record-high TcO4 - uptake selectivity. This material can almost quantitatively remove TcO4 - in the presence of a large excess of NO3 - and SO4 2- . Decontamination experiments confirm that SCU-102 represents the optimal Tc scavenger with the highest reported clean-up efficiency, while first-principle simulations reveal that the origin of the selectivity is the recognition of TcO4 - by the hydrophobic pockets of the structure.
TL;DR: The in vivo full-thickness skin defect model demonstrates that the electroactive and antioxidative pGO-CS/SF scaffold can efficiently enhance wound healing and reduce ROS oxidation, resulting in an improved wound regeneration effect.
Abstract: Wound repair and tissue regeneration are complex processes that involve many physiological signals. Thus, employing novel wound dressings with potent biological activity and physiological signal re...
TL;DR: Density functional theory calculations reveal that carbon atoms close to substituted sulfur atoms are the underlying catalytic active sites for the NRR on S-G, and the related NRR mechanism is also explored.
TL;DR: A novel fractional discrete multivariate grey model based on discrete modelling technique is proposed, which is proved to be an unbiased model with mathematical analysis and stochastic testing and shows that the proposed model outperforms other nine models in the all the real world case studies.
TL;DR: An organic primary explosive featuring a fused-ring structure, 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide, was designed and synthesized through a facile two-step reaction from commercially available reagents, and is low-cost and easy to scale-up.
Abstract: Over the past century, the search for lead-free, environmentally friendly initiating substances has been a highly challenging task in the field of energetic materials. Here, an organic primary explosive featuring a fused-ring structure, 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide, was designed and synthesized through a facile two-step reaction from commercially available reagents. This organic initiating substance meets nearly all of the stringent criteria of environmentally friendly primary explosives for commercial applications: it is free of toxic metals and perchlorate, has a high density, high priming ability, unusual sensitivities towards non-explosive stimuli, excellent environmental resistance, decent thermal stability, high detonation performance, satisfactory flowability and pressure durability, and is low-cost and easy to scale-up. These combined properties and performance measures surpass the current and widely used organic primary explosive, DDNP. The fused-ring organic primary explosive reported herein may find real-world application as an initiating explosive device in the near future.
TL;DR: Compared with the other adsorbents, the as-prepared adsorbent had an excellent tetracycline adsorption capacity, and was expected to be widely applied in the advertisersorption treatment of tetrACYcline wastewater.
TL;DR: Results indicated that carbonate precipitation prior to the other two methods for removal of manganese and ammonia nitrogen showed superior efficiency and economic evaluation reveals that the treatment cost was 9.316 $ m-3 when carbonate and phosphate was used to remove manganes and ammonia ammonia nitrogen from EMMRL.
TL;DR: In this article, a hierarchical hollow nanostructure composed of δ-MnO2 nanosheets deposited by in-situ growth on hollow carbon nanofibers was facilely synthesized using the hydrothermal method.
TL;DR: The unique solvability, energy stability are established for the proposed numerical scheme, and an optimal rate convergence analysis is derived in the $\ell^\infty (0,T; T; H_h^2)$ norm.
TL;DR: Wang et al. as discussed by the authors evaluated the efficiency of a new tree-based soft computing model, Light Gradient Boosting Machine (LightGBM), for estimating daily ETo using limited local and external (cross-station) meteorological data from 49 weather stations in humid subtropical region of China.
TL;DR: In this article, a dumbbell-like architecture built from nanorods was synthesized by a simple coprecipitation route, and the growth process of the dumbbelllike architecture was investigated by varying the reaction duration time.
TL;DR: In this article, a polyamine and amidoxime groups modified bifunctional polyacrylonitrile-based ion exchange fiber (PAN-P-A) has been successfully synthesized by hydrothermal method for highly efficient extraction of U(VI) from aqueous solution.