A solar-driven photoelectrochemical(PEC)cell is emerging as one of the promising clean hydrogen generation systems.Engineering of semiconductor heterojunctions and surface morphologies of photoelectrodes in a PEC cell...A solar-driven photoelectrochemical(PEC)cell is emerging as one of the promising clean hydrogen generation systems.Engineering of semiconductor heterojunctions and surface morphologies of photoelectrodes in a PEC cell has been a primitive approach to boost its performance.This study presents that a molybdenum disulfide(MoS_(2))nanoflakes photoanode on 3-dimensional(3D)porous carbon spun fabric(CSF)as a substrate effectively enhances hydrogen generations due to sufficiently enlarged surface area.MoS_(2)is grown on CSFs utilizing a hydrothermal method.Among three different MoS_(2)coating morphologies depending on the amount of MoS_(2)precursor and hydrothermal growth time,film shape MoS_(2)on CSFs had the largest surface area,exhibiting the highest photocurrent density of 26.48 mA/cm^(2)and the highest applied bias photon-to-current efficiency(ABPE)efficiency of 5.32%at 0.43 VRHE.Furthermore,with a two-step growth method of sputtering and a subsequent hydrothermal coating,continuous TiO_(2)/MoS_(20 heterojunctions on a porous CSF further promoted the photoelectrochemical performances due to their optimized bandgap alignments.Enlarged surface area,enhanced charge transfer,and utilization of visible light enable a highly efficient MoS_(2)/TiO_(2)/CSF photoanode with a photocurrent density of 33.81 mA/cm^(2)and an ABPE of 6.97%at 0.87 VRHE.The hydrogen generation amount of the PEC cell with MoS_(2)/TiO_(2)/CSF photoanode is 225.4μmol/L after light irradiation of 60 s.展开更多
We prot）ose a security-enhanced double-random phase encryption （DRPE） scheme using orthogonally encoded image and electronically synthesized key data to cope with the security problem of DRPE technique caused by fi...We prot）ose a security-enhanced double-random phase encryption （DRPE） scheme using orthogonally encoded image and electronically synthesized key data to cope with the security problem of DRPE technique caused by fixed double-random phase masks for eneryption. In the proposed scheme, we adopt the electronically synthesized key to frequently update the phase mask using a spatial light modulator, and also employ the orthogonal encoding technique to encode the image and electronically synthesized key data, which can enhance the security of both data. We provide detailed procedures for eneryption and decryption of the proposed scheme, and provide the simulation results to show the eneryption effects of the proposed scheme.展开更多
基金supported by the KIST Institution Program(2E32634,2E33323,2E32942)Brain Pool program funded by the Ministry of Science and ICT through the NRF(2020H1D3A1A04080324)Cooperation foundation creation project through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(RS-2023-00239634).
文摘A solar-driven photoelectrochemical(PEC)cell is emerging as one of the promising clean hydrogen generation systems.Engineering of semiconductor heterojunctions and surface morphologies of photoelectrodes in a PEC cell has been a primitive approach to boost its performance.This study presents that a molybdenum disulfide(MoS_(2))nanoflakes photoanode on 3-dimensional(3D)porous carbon spun fabric(CSF)as a substrate effectively enhances hydrogen generations due to sufficiently enlarged surface area.MoS_(2)is grown on CSFs utilizing a hydrothermal method.Among three different MoS_(2)coating morphologies depending on the amount of MoS_(2)precursor and hydrothermal growth time,film shape MoS_(2)on CSFs had the largest surface area,exhibiting the highest photocurrent density of 26.48 mA/cm^(2)and the highest applied bias photon-to-current efficiency(ABPE)efficiency of 5.32%at 0.43 VRHE.Furthermore,with a two-step growth method of sputtering and a subsequent hydrothermal coating,continuous TiO_(2)/MoS_(20 heterojunctions on a porous CSF further promoted the photoelectrochemical performances due to their optimized bandgap alignments.Enlarged surface area,enhanced charge transfer,and utilization of visible light enable a highly efficient MoS_(2)/TiO_(2)/CSF photoanode with a photocurrent density of 33.81 mA/cm^(2)and an ABPE of 6.97%at 0.87 VRHE.The hydrogen generation amount of the PEC cell with MoS_(2)/TiO_(2)/CSF photoanode is 225.4μmol/L after light irradiation of 60 s.
基金supported in part by the Basic Science Research Program through the National Research Foundation of Korea Funded by the Ministry of Science,ICT & Future Planning(No.2011-0030079)the Ministry of Education(No.NRF-2013R1A1A2057549)
文摘We prot）ose a security-enhanced double-random phase encryption （DRPE） scheme using orthogonally encoded image and electronically synthesized key data to cope with the security problem of DRPE technique caused by fixed double-random phase masks for eneryption. In the proposed scheme, we adopt the electronically synthesized key to frequently update the phase mask using a spatial light modulator, and also employ the orthogonal encoding technique to encode the image and electronically synthesized key data, which can enhance the security of both data. We provide detailed procedures for eneryption and decryption of the proposed scheme, and provide the simulation results to show the eneryption effects of the proposed scheme.
