Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by...Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by prevailing methodologies is normally of polycrystalline nature with high nucleation density and limited domain size,which significantly handicaps its overall properties and device performances.Herein,we report an oxygen-assisted CVD strategy to allow the direct synthesis of 6-inch-scale graphene glass harvesting markedly increased graphene domain size(from 0.2 to 1.8μm).Significantly,as-produced graphene glass attains record high electrical conductivity(realizing a sheet resistance of 900Ω·sq^(-1)at a visible-light transmittance of 92%)amongst the state-of-the-art counterparts,readily serving as transparent electrodes for fabricating high-performance optical filter devices.This work might open a new avenue for the scalable production and application of emerging graphene glass materials with high quality and low cost.展开更多
This paper deals with the characterisation and study of physico-chemical stability of ceramic filters from clays and rice husk obtained from the far north region of Cameroon (Logone Valley) and their application in po...This paper deals with the characterisation and study of physico-chemical stability of ceramic filters from clays and rice husk obtained from the far north region of Cameroon (Logone Valley) and their application in potable water treatment. Clays from Mouka were characterized by FTIR analysis. The results showed that the filter formulated with a mixture containing 80% clay and 20% rice husk of 100 μm in size each gave the lowest filter shrinkage rate;these formulated filters were chosen for the remaining work. Leaching tests showed that with filters at a sintering temperature of 830°C the leaching was not observed under neutral (pH 6.8) and acidic (pH 5) conditions as compared to 950°C and 1000°C where the leaching was observed. In basic (pH 9) condition, all the filters obtained released ions. Leaching tests revealed that the conductivity of the leachate for the filters sintered at 830°C was lower than those sintered at 950°C and 1000°C. Meanwhile, conductivity decreases with increasing sintering temperature (temperature up to 830°C) due to the fact that ceramization starts as from 850°C that leads to an amorphous state that favours chemical stability, the leaching ions were Fe2+, Ca2+, Mg2+ and Al3+. The ceramic filters sintered at 950°C were applied to the filtration of water and the performance in terms of turbidity reduction was 95% and the flow rate after 50 minutes was 100 × 10−3 L/h.展开更多
The objective of this paper was to investigate the practicability of coagulation-immersed membrane process during low-temperature period through the study of steady operation,chemical cleaning methods,water quality an...The objective of this paper was to investigate the practicability of coagulation-immersed membrane process during low-temperature period through the study of steady operation,chemical cleaning methods,water quality and agent consumption.Experimental results showed that:membrane performance decreases with the reduction of temperature,but low temperature has little effect on stable operation of immersed membrane when coagulation as pretreatment.EFM with 1200 mg/L sodium hypochlorite after every 48 filtration cycles was made for reducing membrane fouling efficiently,and the method,with 1.5% sodium hydroxide and 3500 mg/L sodium hypochlorite for 10 h and then 2% hydrochloric acid for 4 h,is an appropriate cleaning method under low temperature.Compared with convention treatment process,immersed membrane process not only has same agent consumption,but also permeated water quality is more superior such as fine removal effect on turbidity with average 0.10 NTU.Therefore,coagulation-immersed membrane process is more appropriate for increasing water quality demand and the treatment of low turbidity and low temperature water.展开更多
基金the National Key Research and Development Program of China(No.2016YFA0200103)the National Natural Science Foundation of China(Nos.61527814,51702225,51432002,61474109,51290272,51502007,11474274,51520105003,51672007)+3 种基金National Equipment Program of China(No.ZDYZ2015-1)Beijing Municipal Science Technology Planning Project(Nos.Z 161100002116020,Z161100002116032)Beijing Natural Science Foundation(No.4182063)and Natural Science Foundation of Jiangsu Province(No.BK 20170336).
文摘Growing high quality graphene films directly on glass by chemical vapor deposition(CVD)meets a growing demand for constructing high-performance electronic and optoelectronic devices.However,the graphene synthesized by prevailing methodologies is normally of polycrystalline nature with high nucleation density and limited domain size,which significantly handicaps its overall properties and device performances.Herein,we report an oxygen-assisted CVD strategy to allow the direct synthesis of 6-inch-scale graphene glass harvesting markedly increased graphene domain size(from 0.2 to 1.8μm).Significantly,as-produced graphene glass attains record high electrical conductivity(realizing a sheet resistance of 900Ω·sq^(-1)at a visible-light transmittance of 92%)amongst the state-of-the-art counterparts,readily serving as transparent electrodes for fabricating high-performance optical filter devices.This work might open a new avenue for the scalable production and application of emerging graphene glass materials with high quality and low cost.
文摘This paper deals with the characterisation and study of physico-chemical stability of ceramic filters from clays and rice husk obtained from the far north region of Cameroon (Logone Valley) and their application in potable water treatment. Clays from Mouka were characterized by FTIR analysis. The results showed that the filter formulated with a mixture containing 80% clay and 20% rice husk of 100 μm in size each gave the lowest filter shrinkage rate;these formulated filters were chosen for the remaining work. Leaching tests showed that with filters at a sintering temperature of 830°C the leaching was not observed under neutral (pH 6.8) and acidic (pH 5) conditions as compared to 950°C and 1000°C where the leaching was observed. In basic (pH 9) condition, all the filters obtained released ions. Leaching tests revealed that the conductivity of the leachate for the filters sintered at 830°C was lower than those sintered at 950°C and 1000°C. Meanwhile, conductivity decreases with increasing sintering temperature (temperature up to 830°C) due to the fact that ceramization starts as from 850°C that leads to an amorphous state that favours chemical stability, the leaching ions were Fe2+, Ca2+, Mg2+ and Al3+. The ceramic filters sintered at 950°C were applied to the filtration of water and the performance in terms of turbidity reduction was 95% and the flow rate after 50 minutes was 100 × 10−3 L/h.
基金Sponsored by the Tianjin Municipal Science and Technology Commission (Grant No. 05FZZDSH00500)
文摘The objective of this paper was to investigate the practicability of coagulation-immersed membrane process during low-temperature period through the study of steady operation,chemical cleaning methods,water quality and agent consumption.Experimental results showed that:membrane performance decreases with the reduction of temperature,but low temperature has little effect on stable operation of immersed membrane when coagulation as pretreatment.EFM with 1200 mg/L sodium hypochlorite after every 48 filtration cycles was made for reducing membrane fouling efficiently,and the method,with 1.5% sodium hydroxide and 3500 mg/L sodium hypochlorite for 10 h and then 2% hydrochloric acid for 4 h,is an appropriate cleaning method under low temperature.Compared with convention treatment process,immersed membrane process not only has same agent consumption,but also permeated water quality is more superior such as fine removal effect on turbidity with average 0.10 NTU.Therefore,coagulation-immersed membrane process is more appropriate for increasing water quality demand and the treatment of low turbidity and low temperature water.
