52 results match your criteria: "Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University)[Affiliation]"

It has been reported that the self-assembly pattern of light levitating droplet clusters above the hot gas-liquid interface is dependent on the quantity of droplets. However, the already-reported theoretical explanation of the quantity-dependent self-assembly pattern cannot work well when the quantity of the light levitating droplet exceeds 15. Herein, we propose a new theoretical perspective to understand the self-assembly of a light levitating droplet cluster by referring to the classical densest packing problem of identical rigid circles in a larger circle with the introduction of the minimum total potential energy principle.

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Optofluidics, which utilizes the interactions between light and fluids to realize various functions, has garnered increasing attention owing to the advantages of operational simplicity, exceptional flexibility, rapid response, etc. As one of the typical light-fluid interactions, the localized photothermal effect serving as a stimulus has been widely used for fluid manipulation. Particularly, significant progress on photothermal-driven droplet manipulation has been made.

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The rational design of photocatalysts for improving the conversion of solar energy into hydrogen is a promising route for achieving carbon neutrality. Herein, we couple plasmonic titanium nitride (TiN) with highly crystalline potassium-doped polymeric carbon nitride (PPCN) to construct a PPCN/TiN ohmic junction. Such an ohmic junction not only broadens the absorption spectrum but also inhibits the recombination of electrons and holes.

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Nanofluids-based direct absorption solar collectors are promising candidates for medium-high-temperature solar energy harvesting. However, nanofluids' complicated preparation process and undesirable high-temperature stability have hindered their practical applications. Herein, we propose a facile method for synthesizing gold/carbon quantum dots (Au-CQDs) nanofluids by directly carbonizing the base fluid and spontaneously assembling with Au nanoparticles (AuNPs) triggered by high temperatures.

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Weather data errors affect energy management by influencing the accuracy of building energy predictions. This study presents a long short-term memory (LSTM) prediction model based on the "Energy Detective" dataset (Shanghai, China) and neighboring weather station data. The study analyzes the errors of different weather data sources (Detective and A) at the same latitude and longitude.

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A lack of available information on heating, ventilation, and air-conditioning (HVAC) systems can affect the performance of data-driven fault-tolerant control (FTC) models. This study proposed an in situ selective incremental calibration (ISIC) strategy. Faults were introduced into the indoor air (Ttz1) thermostat and supply air temperature (Tsa) and chilled water supply air temperature (Tchws) sensors of a central air-conditioning system.

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Unraveling the effect of particle size of active metals in Ni/MgO on methane activation and carbon growth mechanism.

Phys Chem Chem Phys

January 2024

Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education of China, Chongqing University, Chongqing 400044, China.

For dry reforming of methane, the active metal particle size of the catalyst has a significant effect on both the reaction activity and the resistance to carbon deposition. In this study, nickel particles of different sizes (Ni13, Ni25, and Ni37) supported on the MgO(100) slab are used to study the mechanism of CH activation and carbon growth based on DFT theoretical calculations. According to the results, the energy of adsorption for reaction intermediates changes depending on the size of the active metal.

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FeO/carbon-decorated graphene boosts photothermal conversion and storage of phase change materials.

J Colloid Interface Sci

March 2024

Institute of Advanced Materials, Beijing Normal University, Beijing 100875, China; Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education of China, Chongqing University, Chongqing 400044, China. Electronic address:

Pristine organic phase change materials (PCMs) are difficult to complete photothermal conversion and storage. To upgrade their photothermal conversion and storage capacity, we developed Fe-MOF (metal-organic framework) derived FeO/C-decorated graphene (GP) based composite PCMs toward solar energy harvesting. Graphene is an excellent phonon conductor, and FeO/C-GP as a photon capturer exhibits strong full-spectrum absorption.

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Flexible control of droplet transportation is crucial in various applications but is constrained by liquid-solid friction. The development of biomimetic lubricant-impregnated slippery surfaces provides a new solution for flexible manipulation of droplet transportation. Herein, a light strategy is reported for flexibly controlling droplet transportation on photosensitive lubricant-impregnated slippery surfaces.

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Flexible and precise manipulation of droplet transport is of significance for scientific and engineering applications, but real-time and on-demand droplet manipulation remains a challenge. Herein, we report a strategy using light for the outstanding manipulation of binary droplet motion on a high-energy surface and reveal the underlying mechanism. Upon irradiation to a substrate by a focused light beam, the substrate can provide a localized heating source photothermal conversion, and a binary droplet can be flexibly transported on a high-energy surface with free contact-line pinning, exhibiting light-propelled droplet transport.

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High-throughput droplet splitting and controllable transport of generated microdroplets on open surfaces are crucial in a broad spectrum of applications. Herein, a light strategy for controlling high-throughput splitting of binary droplets and transport of generated microdroplets on a high-energy substrate endowed by a localized photothermal effect is reported. Strong Marangoni flow as a result of the surface tension gradient and limited inward flow at the droplet bottom as a result of the significant viscous effect are together responsible for binary droplet splitting.

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Due to energy constraints and people's increasing requirements for indoor thermal comfort, improving energy efficiency while ensuring thermal comfort has become the focus of research in the design and operation of HVAC systems. This study took office rooms with few people occupying them in Wuhan as the research object. The EnergyPlus-Fluent co-simulation method was used to study the impact of 12 forms of air distribution on the thermal environment and air-conditioner energy consumption.

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Effects of Cu ratios on the C-C growth mechanism on copper-nickel bimetallic surfaces.

Phys Chem Chem Phys

July 2023

Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education of China, Chongqing University, Chongqing 400044, China.

The adsorption and growth mechanisms of C ( = 1-6) on different Cu-Ni surfaces are calculated by density functional theory (DFT). The results demonstrate that Cu doping affects the growth mechanism of the deposited carbon on the catalyst surface. Firstly, the addition of Cu weakens the interaction between C and the adsorbed surface, which is proved by the results of density of states (DOS) and partial density of states (PDOS).

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Precision manipulation of particle-enrichment patterns in droplets is challenging but important in biochemical analysis and clinical diagnosis. Herein, a light strategy for precisely manipulating particle enrichment patterns is reported. Focused laser irradiation to the droplet induces a Marangoni flow owing to a localized photothermal effect, which carries in-droplet particles and concentrates them at the laser-spot-acted region.

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Gas diffusion TiO photoanode for photocatalytic fuel cell towards simultaneous VOCs degradation and electricity generation.

J Hazard Mater

April 2023

Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030, China; Institute of Engineering Thermophysics, School of Energy and Power Engineering, Chongqing University, Chongqing 400030, China.

In this work, a photocatalytic fuel cell (PFC) with a gas diffusion TiO photoanode is proposed to directly convert chemical energy contained in volatile organic compounds into electricity by using solar energy. The gas diffusion TiO photoanode is prepared by coating TiO nanoparticles onto Ti mesh, whose intrinsic porous structure allows for gaseous pollutants to directly transfer inside the photoanode and thereby enhances mass transport. The feasibility of the developed gas diffusion photoanode is demonstrated by degrading toluene as a model gaseous pollutant.

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Bioelectrochemical systems (BESs) are promising devices for wastewater treatment and bio-energy production. Since various processes are interacted and affect the overall performance of the device, the development of theoretical modeling is an efficient approach to understand the fundamental mechanisms that govern the performance of the BES. This review aims to summarize the physiochemical principle and mathematical method in BES models, which is of great importance for the establishment of an accurate model while has received little attention in previous reviews.

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The flexible and precise manipulation of droplets on an air-liquid interface with complex functions remains challenging. Herein, we propose a smart strategy for excellently manipulating target droplets by decanol liquid lenses. A moveable surface tension gradient field generated by decanol liquid lenses is responsible for realizing various functions of transportation, launching and splitting of target droplets.

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Controlling crystal morphology is crucial in analytical chemistry and smart materials synthesis, etc. However, flexible manipulation of 3D crystal morphology still remains challenging. Herein, we present a novel and facile light strategy for droplet evaporative crystallization to manipulate macroscopic crystal morphology on photosensitive hydrophobic substrate possessing photothermal conversion property.

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Light droplet levitation is an elegant technique allowing for contact-less manipulation in a wall-free environment. However, direct generation of light levitated droplets remains limited by small-curvature interface and underlying mechanism remains unclear. Here we report that small-curvature interface limitation encountered in liquid water is overcome by using liquids with extremely small saturated vapor pressure, which allows for direct generation of light levitated droplets above large-curvature interface.

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Flexibly and precisely manipulating 3D droplet transportation is a fundamental challenge for broad implications in diagnostics, drug delivery, bioengineering, etc. Herein, a light method is developed for manipulating a droplet to make it behave like a submarine. This light method enables flexible 3D transportation, stable suspension, and floating of a droplet, which can be freely altered.

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Photo-thermo catalytic hydrogen production represents one of the most promising routes for channeling solar energy but typically suffers from high reaction temperatures. In this work, we develop photo-thermo catalytic hydrogen production at low temperatures by cost-effective, nonplasmonic, and metal-free nitrogen-doped carbon materials (CNO). We demonstrate that due to the photothermal conversion of CNO, carrier generation is improved and electron migration is enhanced to suppress the recombination of electron-hole pairs, both of which promote hydrogen production by photocatalysis, while generated hydrogen radicals facilitate the regeneration of active sites for hydrogen production by thermocatalysis.

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A review on biological recycling in agricultural waste-based biohydrogen production: Recent developments.

Bioresour Technol

March 2022

Key Laboratory of New Materials and Facilities for Rural Renewable Energy of Ministry of Agriculture and Rural Affairs, College of Mechanical & Electrical Engineering, Henan Agricultural University, Zhengzhou 450002, China; Henan International Joint Laboratory of Biomass Energy and Nanomaterials, Henan Agricultural University, Zhengzhou 450002, China; Collaborative Innovation Center of Biomass Energy, Henan Province, Zhengzhou 450002, China.

Hydrogen has become a research highlight by virtue of its clean energy production technology and high energy content. The technology of biohydrogen production from biological waste via fermentation has lower costs, provides environment-friendly methods regarding energy balance, and creates a pathway for sustainable utilization of massive agricultural waste. However, biohydrogen production is generally limited by lower productivity.

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The light-enabled droplet levitation shows promising potential in applications in biotechnology, clinical medicine, and nanomaterials. In particular, light-levitated droplets have good followability with a moving laser beam, resulting in flexibility in manipulating their motion. However, it is still unclear whether there exists an upper limit to the light-levitated droplet motion with a moving laser beam.

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In this study, a contactless, flexible, and interference-free light fueled method has been developed to enhance the mixing between the ssDNA and dynabeads in a droplet, which enables rapid probe preparation for promoting the probe technology based on open surface droplet microfluidics. In this light fueled method, the use of the photothermal effect of a focused infrared laser can easily create non-uniform temperature distribution and accordingly the surface tension gradient over the interface as a result of the localized heating effect, which thereby initiates the Marangoni flow in a droplet. Experimental results confirm that the light-induced Marangoni flow greatly enhances the mixing, ensuring rapid and efficient binding between the ssDNA and dynabeads.

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The green production of ammonia, in an electrochemical flow cell under ambient conditions, is a promising way to replace the energy-intensive Haber-Bosch process. In the operation of this flow cell with an alkaline electrolyte, water is produced at the anode but also required as an essential reactant at the cathode for nitrogen reduction. Hence, water from the anode is expected to diffuse through the membrane to the cathode to compensate for the water needed for nitrogen reduction.

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