The chalcogenides of platinum-group metals(PGMs)have been known to be present in minerals and the intermediate products of refining.Over recent years,their applications in various fields,including catalysis,have been ...The chalcogenides of platinum-group metals(PGMs)have been known to be present in minerals and the intermediate products of refining.Over recent years,their applications in various fields,including catalysis,have been explored.Given that certain PGM chalcogenides behave as compound semiconductors,they can be used as materials for photodetectors.In this study,RuS_(2),featuring a bandgap suitable for near-infrared photodetectors,was prepared by forming Ru on a SiO_(2)/Si substrate via the atomic layer deposition method using[Ru(TMM)(CO)_(3)]as the precursor.Annealing was conducted at 800℃ for 1 h under H_(2)S flow.High-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)analysis clearly confirmed that the as-deposited hexagonal close-packed(hcp)Ru transformed to cubic RuS_(2) after post-annealing.The surface morphologies,chemical states,and electrical and optical properties of RuS_(2) were investigated.The influence of the metallic Ru surface morphology prior to sulfurization on the reaction between Ru and H_(2)S was also discussed.To evaluate the potential of using RuS_(2) as a photodetector,a photodetector was fabricated by forming electrodes on RuS_(2) to measure its photocurrent under near-infrared light.Thus,RuS_(2) was proven to exhibit a short response time(59μs)and generate a photocurrent of 84 nA under near-infrared light at 940 nm.展开更多
A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobi...A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobic respiration. The fluorescent signal of resorufin reduced by planktonic cells and microorganisms of biofilm showed linearity, indicating its feasibility to monitor biofouling in a RO system. For the application of the method to the lab-scale RO system, the injection concentration of resazurin and the injection flow rate were optimized. Biofilm on RO membranes continuously operated in a lab-scale RO system was estimated by resorufin fluorescence under optimized detection condition. As a result,resorufin fluorescence on RO membrane showed a significant increase in which the permeability of RO system decreased by 30.48%. Moreover, it represented the development of biofilm as much as conventional biofilm parameters such as adenosine triphosphate,extracellular polymeric substances, and biofilm thickness. The proposed method could be used as a sensitive and low-cost technology to monitor biofouling without autopsy of membranes.展开更多
基金supported by TANAKA Kikinzoku Kogyo K.K.Also by the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.NRF-2021R1I1A1A01057933)。
文摘The chalcogenides of platinum-group metals(PGMs)have been known to be present in minerals and the intermediate products of refining.Over recent years,their applications in various fields,including catalysis,have been explored.Given that certain PGM chalcogenides behave as compound semiconductors,they can be used as materials for photodetectors.In this study,RuS_(2),featuring a bandgap suitable for near-infrared photodetectors,was prepared by forming Ru on a SiO_(2)/Si substrate via the atomic layer deposition method using[Ru(TMM)(CO)_(3)]as the precursor.Annealing was conducted at 800℃ for 1 h under H_(2)S flow.High-resolution transmission electron microscopy(HRTEM)and X-ray diffraction(XRD)analysis clearly confirmed that the as-deposited hexagonal close-packed(hcp)Ru transformed to cubic RuS_(2) after post-annealing.The surface morphologies,chemical states,and electrical and optical properties of RuS_(2) were investigated.The influence of the metallic Ru surface morphology prior to sulfurization on the reaction between Ru and H_(2)S was also discussed.To evaluate the potential of using RuS_(2) as a photodetector,a photodetector was fabricated by forming electrodes on RuS_(2) to measure its photocurrent under near-infrared light.Thus,RuS_(2) was proven to exhibit a short response time(59μs)and generate a photocurrent of 84 nA under near-infrared light at 940 nm.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No. 2018R1A2B2005745)
文摘A monitoring method of biofouling in reverse osmosis(RO) system was proposed based on the fluorescent signal of resorufin, which is reduced by nicotinamide adenine dinucleotide released from viable cells during aerobic respiration. The fluorescent signal of resorufin reduced by planktonic cells and microorganisms of biofilm showed linearity, indicating its feasibility to monitor biofouling in a RO system. For the application of the method to the lab-scale RO system, the injection concentration of resazurin and the injection flow rate were optimized. Biofilm on RO membranes continuously operated in a lab-scale RO system was estimated by resorufin fluorescence under optimized detection condition. As a result,resorufin fluorescence on RO membrane showed a significant increase in which the permeability of RO system decreased by 30.48%. Moreover, it represented the development of biofilm as much as conventional biofilm parameters such as adenosine triphosphate,extracellular polymeric substances, and biofilm thickness. The proposed method could be used as a sensitive and low-cost technology to monitor biofouling without autopsy of membranes.
