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Zinc Rhodium Oxide and Its Possibility as a Constituent Photocatalyst for Carbon Dioxide Reduction using Water as an Electron Source
摘要： We evaluated the potential of zinc rhodium oxide (ZnRh2O4) as a carbon dioxide (CO2) reduction photocatalyst with the aid of triethanolamine (TEOA) as an electron donor and demonstrated that ZnRh2O4 was able to reduce CO2 to carbon monoxide (CO) under infrared light. Gold (Au) loading onto ZnRh2O4 greatly enhanced the CO2 reduction activity. Also, CO2 reduction was examined over a composite of ZnRh2O4 and bismuth vanadium oxide (Bi4V2O11) with inserted Au (ZnRh2O4/Au/Bi4V2O11) using H2O as the electron source, which led to the successful evolution of CO.
关键词： Carbon monoxide,Methane,Triethanolamine,Gold,Carbon dioxide reduction,Zinc rhodium oxide
更新于2025-11-19 16:51:07
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Characterization of atypical polyaniline nano-structures prepared via advanced techniques
摘要： Conductive polymers had been the topic of a vast number of investigations during the last decades, so, the synthesis of conducting polymers and study of their physical properties has been of prime importance. One of these conductive polymers is polyaniline. The current work is to prepare polyaniline (PANI) nanostructured material via four different preparation techniques which were sol-gel, rapid mixing, sonochemical and supercritical carbon dioxide (SC-CO2) assisted polymerization. The morphology of the prepared PANI samples was determined using Transmission electron microscopy (TEM) and Scanning Electron Microscope (SEM). The molecular structure of prepared PANI samples was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The electrical conductivity of the synthesized samples was assessed by using the four-probe method at room temperature. The surface area of the prepared samples was determined using Brunauer Emmett Teller (BET). The characterization results of the prepared PANI con?rm that the morphology, chemical composition, crystallinity, conductivity and surface area were altered signi?cantly as a consequence of its synthesis via atypical techniques.
关键词： Supercritical carbon dioxide assisted polymerization,Nanoparticles,Sonochemical,Polyaniline nano-structures,Nano?bers,Polyaniline characterization,Nanorods,Sol gel,Rapid mixing polymerization
更新于2025-09-23 15:23:52
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Efficient Conversion of CO <sub/>2</sub> to Methane Photocatalyzed by Conductive Black Titania
摘要： One of the major challenges encountered in CO2 utilization is the development of available and cost-efficient catalysts with sufficient activity, selectivity, and stability for the generation of useful methane. Here, conductive black titania, TiO2@x, is found to be efficient in photocatalyzing the reduction of CO2 to CH4. This unique material comprises a crystalline core–amorphous shell structure (TiO2@TiO2@x) with numerous surface oxygen vacancies, which facilitates the adsorption and chemical activation of CO2 molecules. Under full solar irradiation, the optimized 500-TiO2@x material with narrowed band gap and intermediate states below the conduction band tail exhibits a high space-time yield of CH4 of 14.3 mmol g@1 h@1, with 74 % selectivity and excellent photostability. The present findings can make a significant contribution, not only to develop the surface electron-modified black TiO2 catalyst to boost photocatalytic efficiency, but also to establish a really viable and convenient CH4 production process for CO2 conversion and renewable solar energy storage.
关键词： oxygen vacancies,photocatalysis,carbon dioxide chemistry,conductive black titania,methane generation
更新于2025-09-23 15:23:52
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A Selective Earth-Abundant System for CO <sub/>2</sub> Reduction: Comparing Photo- and Electrocatalytic Processes
摘要： The valorization of CO2 via photo- or electrocatalytic reduction constitutes a promising approach toward the sustainable production of fuels or value-added chemicals using intermittent renewable energy sources. For this purpose, molecular catalysts are generally studied independently with respect to the photo- or the electrochemical application, although a unifying approach would be much more effective with respect to the mechanistic understanding and the catalyst optimization. In this context, we present a combined photo- and electrocatalytic study of three Mn diimine catalysts, which demonstrates the synergistic interplay between the two methods. The photochemical part of our study involves the development of a catalytic system containing a heteroleptic Cu photosensitizer and the sacrificial BIH reagent. The system shows exclusive selectivity for CO generation and renders turnover numbers which are among the highest reported thus far within the group of fully earth-abundant photocatalytic systems. The electrochemical part of our investigations complements the mechanistic understanding of the photochemical process and demonstrates that in the present case the sacrificial reagent, the photosensitizer and the irradiation source can be replaced by the electrode and a weak Br?nstedt acid.
关键词： photocatalysis,electrocatalysis,manganese,copper,carbon dioxide utilization
更新于2025-09-23 15:23:52
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[Energy, Environment, and Sustainability] Advances in Solar Energy Research || Supercritical Carbon Dioxide Solar Thermal Power Generation—Overview of the Technology and Microchannel Receiver Development
摘要： The supercritical carbon dioxide (sCO2) power cycle is being considered for solar thermal central receiver systems in the United States. The cycle lends to increased high-temperature input that is expected of the next-generation concentrating solar thermal power (CSP) systems. Power block efficiencies of about 50% can be achieved for recompression cycles at an input temperature of approximately 720 °C. Additionally, the power block is compact and less complex, raising the possibility of using thermal-storage-coupled CSP sCO2 technologies for modular (*100 MW) peak-load power plants. Three pathways toward providing solar thermal input to the sCO2 cycle have been proposed by various research groups—the molten salt receiver pathway, the solid particle receiver pathway, and the gas-phase receiver pathway. The first two technologies have the advantage of sensible thermal storage within the solid/fluid medium passing through the receiver. In the gas receiver pathway, there is a need for coupling a sensible or latent heat storage technology. Several key technologies are needed to enable the realization of the sCO2 solar thermal technology, key among them being the receiver and thermal storage. In this chapter, some of the key gas-phase receiver technologies are discussed. The group’s past and recent work on the development of microchannel solar thermal receivers for sCO2 is emphasized.
关键词： Solar thermal,Efficiency,Supercritical carbon dioxide,Microchannel,Receiver,Concentrating solar power
更新于2025-09-23 15:21:21
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The rapid development of the photovoltaic industry in China and related carbon dioxide abatement costs
摘要： There is a consensus within the international community that replacing traditional fossil energy with renewable energy, such as photovoltaic energy, will help mitigate climate change. However, the literature addressing the rapid development issues of the photovoltaic industry and related carbon dioxide abatement costs is limited. China is currently the largest photovoltaic producer and consumer in the world, hence suitable as our research object. In this paper, a fixed effect panel model with provincial panel data during the period 2012–2016 is applied to study the factors that influence China’s photovoltaic industry. The empirical results indicate that carbon dioxide emission mitigation requirements, government subsidies, technological progress, energy substitution, economic growth, and illumination resources promote the development of the photovoltaic industry. We further adapt the cost estimation model to estimate the average carbon dioxide abatement cost of photovoltaic electric power in China at 679.72 yuan/ton in 2015 and 681.88 yuan/ton in 2016. Compared with wind power and biomass energy, photovoltaic electric power is currently less economical for carbon dioxide emission reduction. Moreover, the future carbon dioxide abatement cost is predicted using a scenario analysis at 118.94–259.42 yuan/ton in 2025 and 42.63–171.95 yuan/ton in 2030. Since the carbon dioxide abatement cost in 2030 is in line with the future price level of the carbon trading market, it will be both economical and feasible to use photovoltaic electric power to decrease carbon dioxide emissions in the future.
关键词： Carbon dioxide mitigation requirements,Carbon dioxide abatement cost,Fixed effect panel model,Photovoltaic industry,Scenario analysis
更新于2025-09-23 15:21:01
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Temperature evolution in a pulsed CO<sub>2</sub>-N<sub>2</sub> glow discharge measured using quantum cascade laser absorption spectroscopy
摘要： This work uses in situ narrowband Quantum Cascade Laser (QCL) absorption spectroscopy to study the effect of N2 on the time evolution of gas temperature, rotational temperature and the vibrational temperatures of CO2 and CO in a pulsed glow discharge. Three colinear QCLs are used to scan three regions of about 1 cm?1 between 2179.20 and 2253.51 cm?1, including (v1, vl2 2 , v3 + 1) → (v1, vl2 2 , v3) CO2 transitions up to the asymmetric stretch level v3 = 6, as well as (vCO) → (vCO +1) CO transitions up to vCO = 1. A fitting routine is used to extract temperatures from the measured absorption spectra. The time resolved measurements are performed in CO2, admixed with up to 90% N2, with the plasma operated with a 5-10 ms on-off cycle, a discharge current of 50 mA and a pressure of around 6.7 mbar. The time evolution of the gas temperature has been measured and agrees well with the time evolution of the rotational temperature. The asymmetric stretch vibrational temperature T3 of CO2 reaches a maximum of 1060 K at 0.7 ms for pure CO2, while T3 goes up to 2250 K for a N2 content of 90% and stays constant until the plasma is switched off. Both T3 and the vibrational temperature of CO TCO show a clear non-equilibrium with respect to the rotational temperature Trot. Both do not equilibrate with the rotational temperature Trot between consecutive plasma cycles for a N2 content above 70%, although T3 and TCO always equilibrate with each other in the afterglow. The symmetric stretch and bending mode temperature T12 is elevated more with respect to the rotational temperature for increasing N2 content, while the maximum of the rotational temperature decreases for increasing N2 admixtures, which might be attributed to the energy stored in the vibrational modes of N2, CO2 and CO. Additionally, an indication of an increase in the total pressure during the plasma on-time due to heating and a subsequent decrease in the afterglow due to cooling was found for a pure CO2 plasma.
关键词： glow discharge,carbon dioxide plasma,vibrational temperature,gas temperature,quantum cascade laser
更新于2025-09-23 15:21:01
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Boosting the efficiency of solution-based CZTSSe solar cells by using supercritical carbon dioxide treatment
摘要： Cu2ZnSn(S,Se)4 (CZTSSe) solar cells are receiving considerable attention in recent years, owing to the low cost and toxicity as well as high abundance of their constituent elements. Solution-based (mainly precursor solution) methods have been widely used in the fabrication of CZTSSe-based thin film solar cells. Though most record solar cells since 2009 have been achieved using solution-based methods, carbonaceous residues are always formed during post deposition treatment (PDT). These carbonaceous residues are detrimental to grain growth of CZTSSe to form large grains. The presence of unwanted small grains layers will increase the series resistance and reduce the fill factor of the solar cell, thus consequently hindering high efficiency in CZTSSe solar cells. Herein, we propose “green” supercritical carbon dioxide (SCCO2) treatment to overcome the challenge of carbonaceous residues. FT-IR、SEM、XRD and Raman characterizations were used to confirm the reducing of carbonaceous residues in CZTSSe films. The solar cell fabricated from selenized CZTSSe precursor film with SCCO2 treatment under optimal conditions showed the best conversion efficiency of 11.23 % (VOC = 0.456 V, JSC = 36.6 mA/cm2, FF = 67.1 %). To the best of our knowledge, it is the first report on boosting the efficiency of solution-based CZTSSe solar cells by using SCCO2 treatment. In addition, this unique SCCO2 treatment may also bring forth new ideas in other solution-based optoelectronic devices.
关键词： CZTSSe,Cu2ZnSn(S,Se)4,Carbonaceous residues,SCCO2 treatment,Supercritical carbon dioxide treatment
更新于2025-09-23 15:21:01
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Single-Stage Formation of Film Polymer Composites in Supercritical Colloid Solutions of Nanoparticles Obtained by Laser Ablation
摘要： A review of earlier studies is presented together with new results on the creation of highly concentrated colloid solutions with nanoparticles of noble metals (gold and silver) in a supercritical carbon dioxide (SC–CO2) medium and the development of a single-stage method for the production of polymer nanocomposites. The effect of the SC–CO2 density on the dynamics of the formation and decomposition of supercritical fluids (SCFs) of silver and gold nanocolloids in the process of pulsed laser ablation and after its termination is studied. The possibility of the formation of colloids from bimetallic nanoparticles was considered. The effective dielectric permittivity of a colloid solution of silver nanoparticles in SC–CO2 is calculated by the numerical modeling of extinction spectra in the dipole approximation at various densities, with consideration for the size of nanoparticles and the degree of their asphericity. The formation of various film nanocomposites based on a porous copolymer polytetrafluoroethylene—vinylidenefluoride with ruby nanoparticles and two modifications of pure porous polytetrafluoroethylene with silver nanoparticles in the same SCF reactor and with a single technological process is considered.
关键词： bimetallic nanoparticles,film nanocomposites,nanocolloid,supercritical carbon dioxide,porous polymers
更新于2025-09-23 15:21:01
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Equine Surgery || Lasers in Veterinary Surgery
摘要： Surgical lasers facilitate minimally invasive surgery, allow surgical access to otherwise inaccessible areas, and induce tissue interactions, which cannot be obtained with conventional surgical instrumentation. Surgical laser procedures can be performed on an outpatient basis and have eliminated procedures that previously required general anesthesia and hospitalization. Surgeons should be knowledgeable about which procedures can be accomplished with surgical lasers and which are better suited to conventional surgery. This chapter will provide information and guidelines on the use of surgical lasers in equine surgery.
关键词： equine surgery,minimally invasive surgery,carbon dioxide laser,Surgical lasers,neodymium:yttrium-aluminum-garnet laser,holmium:yttrium-aluminum-garnet laser,diode laser
更新于2025-09-23 15:21:01