Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can impr...Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can improve the energy conversion efficiency.Since iron corrodes easily and even self-corrodes to form magnetic iron oxide species and generate corrosion currents,a novel strategy to integrate the hydrogen evolution reaction(HER)with waste Fe upgrading reaction(FUR)is proposed and demonstrated for energy-efficient hydrogen production in neutral media.The heterostructured MoSe_(2)/MoO_(2) grown on carbon cloth(MSM/CC)shows superior HER performance to that of commercial Pt/C at high current densities.By replacing conventional OER with FUR,the potential required to afford the anodic current density of 10 m A cm^(-2)decreases by 95%.The HER/FUR overall reaction shows an ultralow voltage of 0.68 V for 10 m A cm^(-2)with a power equivalent of 2.69 k Wh per m^(3)H_(2).Additionally,the Fe species formed at the anode extract the Rhodamine B(Rh B)pollutant by flocculation and also produce nanosized magnetic powder and beneficiated Rh B for value-adding applications.This work demonstrates both energy-saving hydrogen production and pollutant recycling without carbon emission by a single system and reveals a new direction to integrate hydrogen production with environmental recovery to achieve carbon neutrality.展开更多
Many cities have pledged to achieve carbon neutrality.The urban water industry can also contribute its share to a carbon-neutral future.Using a multi-city time-series analysis approach,this study aims to assess the pr...Many cities have pledged to achieve carbon neutrality.The urban water industry can also contribute its share to a carbon-neutral future.Using a multi-city time-series analysis approach,this study aims to assess the progress and lessons learned from the greenhouse gas(GHG)emissions management of urban water systems in four global cities:Amsterdam,Melbourne,New York City,and Tokyo.These cities are advanced in setting GHG emissions reduction targets and reporting GHG emissions in their water industries.All four cities have reduced the GHG emissions in their water industries,compared with those from more than a decade ago(i.e.,the latest three-year moving averages are 13%–32%lower),although the emissions have“rebounded”multiple times over the years.The emissions reductions were mainly due to various engineering opportunities such as solar and mini-hydro power generation,biogas valorization,sludge digestion and incineration optimization,and aeration system optimization.These cities have recognized the many challenges in reaching carbon-neutrality goals,which include fluctuating water demand and rainfall,more carbon-intensive flood-prevention and water-supply strategies,meeting new air and water quality standards,and revising GHG emissions accounting methods.This study has also shown that it is difficult for the water industry to achieve carbon neutrality on its own.A collaborative approach with other sectors is needed when aiming toward the city’s carbon-neutrality goal.Such an approach involves expanding the usual system boundary of the water industry to externally tap into both engineering and non-engineering opportunities.展开更多
Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry （WFC） system is applied to measure the...Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry （WFC） system is applied to measure the heat load on the electrode system of the ion source and the heat loading components of the beamline. Due to the heat loss in the return water pipe, there are some measuring errors for the current WFC system. In this paper, the errors were measured experimentally and analyzed theoretically, which lay a basis for the exact calculation of beam power deposition distribution and neutralization efficiency.展开更多
Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), in...Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), infrared (IR) spectroscopy, powder X-ray diffraction (XRD), and 57Fe Mssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite (12), but apparently close to those of siliceous ferrihydrite (0.250.5). Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio proposed by Henmi et al. (1981), all the deposits in this study were concluded to be mixtures of various siliceous ferri-hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring waters, the formation conditions of siliceous ferrihydrite were also discussed.展开更多
基金financially supported by the Key Research and Development Program of Hubei Province (2021BAA208)the National Natural Science Foundation of China (52002294,51974208 and U2003130)+3 种基金the Young Top-notch Talent Cultivation Program of Hubei ProvinceKnowledge Innovation Program of Wuhan-Shuguang Project (2022010801020364)the City University of Hong Kong Strategic Research Grant (SRG) (7005505)the City University of Hong Kong Donation Research Grant (DONRMG 9229021)。
文摘Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can improve the energy conversion efficiency.Since iron corrodes easily and even self-corrodes to form magnetic iron oxide species and generate corrosion currents,a novel strategy to integrate the hydrogen evolution reaction(HER)with waste Fe upgrading reaction(FUR)is proposed and demonstrated for energy-efficient hydrogen production in neutral media.The heterostructured MoSe_(2)/MoO_(2) grown on carbon cloth(MSM/CC)shows superior HER performance to that of commercial Pt/C at high current densities.By replacing conventional OER with FUR,the potential required to afford the anodic current density of 10 m A cm^(-2)decreases by 95%.The HER/FUR overall reaction shows an ultralow voltage of 0.68 V for 10 m A cm^(-2)with a power equivalent of 2.69 k Wh per m^(3)H_(2).Additionally,the Fe species formed at the anode extract the Rhodamine B(Rh B)pollutant by flocculation and also produce nanosized magnetic powder and beneficiated Rh B for value-adding applications.This work demonstrates both energy-saving hydrogen production and pollutant recycling without carbon emission by a single system and reveals a new direction to integrate hydrogen production with environmental recovery to achieve carbon neutrality.
基金the National Key Research and Development Program of China(2018YFE0204100).
文摘Many cities have pledged to achieve carbon neutrality.The urban water industry can also contribute its share to a carbon-neutral future.Using a multi-city time-series analysis approach,this study aims to assess the progress and lessons learned from the greenhouse gas(GHG)emissions management of urban water systems in four global cities:Amsterdam,Melbourne,New York City,and Tokyo.These cities are advanced in setting GHG emissions reduction targets and reporting GHG emissions in their water industries.All four cities have reduced the GHG emissions in their water industries,compared with those from more than a decade ago(i.e.,the latest three-year moving averages are 13%–32%lower),although the emissions have“rebounded”multiple times over the years.The emissions reductions were mainly due to various engineering opportunities such as solar and mini-hydro power generation,biogas valorization,sludge digestion and incineration optimization,and aeration system optimization.These cities have recognized the many challenges in reaching carbon-neutrality goals,which include fluctuating water demand and rainfall,more carbon-intensive flood-prevention and water-supply strategies,meeting new air and water quality standards,and revising GHG emissions accounting methods.This study has also shown that it is difficult for the water industry to achieve carbon neutrality on its own.A collaborative approach with other sectors is needed when aiming toward the city’s carbon-neutrality goal.Such an approach involves expanding the usual system boundary of the water industry to externally tap into both engineering and non-engineering opportunities.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2013GB101001)the International Science&Technology Cooperation Program of China(No.2014DFG61950)
文摘Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry （WFC） system is applied to measure the heat load on the electrode system of the ion source and the heat loading components of the beamline. Due to the heat loss in the return water pipe, there are some measuring errors for the current WFC system. In this paper, the errors were measured experimentally and analyzed theoretically, which lay a basis for the exact calculation of beam power deposition distribution and neutralization efficiency.
基金financially supported by the Interdisciplinary Programs in Education and the Projects in Research Development, Kyushu University
文摘Five ferruginous deposit samples formed from neutral hot springs were analyzed to determine whether they consisted of a mixture of silica, hydrous iron oxide or iron silicate by differential thermal analysis (DTA), infrared (IR) spectroscopy, powder X-ray diffraction (XRD), and 57Fe Mssbauer spectroscopy. The Si/Fe atomic ratios of the deposits ranged from 0.25 to 0.45, and were smaller than those of hisingerite (12), but apparently close to those of siliceous ferrihydrite (0.250.5). Si was confirmed to be present as monomeric or oligomeric silicate from the Si-O stretching vibration frequencies on the IR spectra. Judging from the results of DTA, which minerals starting to produce after heating, and a relationship between Si-O stretching vibration frequency and Si/Fe atomic ratio proposed by Henmi et al. (1981), all the deposits in this study were concluded to be mixtures of various siliceous ferri-hydrites with low and high Si/Fe atomic ratios. Moreover, by comparing the chemical properties of hot spring waters, the formation conditions of siliceous ferrihydrite were also discussed.
