Photocatalytic hydrogen generation represents a promising strategy for the establishment of a sustainable and environmentally friendly energy reservoir.However,the current solar-to-hydrogen conversion efficiency is no...Photocatalytic hydrogen generation represents a promising strategy for the establishment of a sustainable and environmentally friendly energy reservoir.However,the current solar-to-hydrogen conversion efficiency is not yet sufficient for practical hydrogen production,highlighting the need for further research and development.Here,we report the synthesis of a Sn-doped TiO_(2)continuous homojunction hollow sphere,achieved through controlled calcination time.The incorporation of a gradient doping profile has been demonstrated to generate a gradient in the band edge energy,facilitating carrier orientation migration.Furthermore,the hollow sphere’s outer and inner sides provide spatially separated reaction sites allowing for the separate acceptance of holes and electrons,which enables the rapid utilization of carriers after separation.As a result,the hollow sphere TiO_(2)with gradient Sn doping exhibits a significantly increased hydrogen production rate of 20.1 mmol·g^(−1)·h^(−1).This study offers a compelling and effective approach to the designing and fabricating highly efficient nanostructured photocatalysts for solar energy conversion applications.展开更多
This paper analyzes the power consumption and delay mechanisms of the successive-approximation （SA） logic of a typical asynchronous SAR ADC, and provides strategies to reduce both of them. Following these strategies...This paper analyzes the power consumption and delay mechanisms of the successive-approximation （SA） logic of a typical asynchronous SAR ADC, and provides strategies to reduce both of them. Following these strategies, a unique direct-pass SA logic is proposed based on a full-swing once-triggered DFF and a self-locking tri-state gate. The unnecessary internal switching power of a typical TSPC DFF, which is commonly used in the SA logic, is avoided. The delay of the ready detector as well as the sequencer is removed from the critical path. A prototype SAR ADC based on the proposed SA logic is fabricated in 130 nm CMOS. It achieves a peak SNDR of 56.3 dB at 1.2 V supply and 65 MS/s sampling rate, and has a total power consumption of 555 μW, while the digital part consumes only 203μW.展开更多
基金the National Natural Science Foundation of China(Nos.22008121,11774173,and 51790492)the National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(No.T2125004)+2 种基金the Fundamental Research Funds for the Central Universities(Nos.30920032204,30920021307,and 30920041115)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(No.2022-K12)the Funding of NJUST(No.TSXK2022D002)for financial support.
文摘Photocatalytic hydrogen generation represents a promising strategy for the establishment of a sustainable and environmentally friendly energy reservoir.However,the current solar-to-hydrogen conversion efficiency is not yet sufficient for practical hydrogen production,highlighting the need for further research and development.Here,we report the synthesis of a Sn-doped TiO_(2)continuous homojunction hollow sphere,achieved through controlled calcination time.The incorporation of a gradient doping profile has been demonstrated to generate a gradient in the band edge energy,facilitating carrier orientation migration.Furthermore,the hollow sphere’s outer and inner sides provide spatially separated reaction sites allowing for the separate acceptance of holes and electrons,which enables the rapid utilization of carriers after separation.As a result,the hollow sphere TiO_(2)with gradient Sn doping exhibits a significantly increased hydrogen production rate of 20.1 mmol·g^(−1)·h^(−1).This study offers a compelling and effective approach to the designing and fabricating highly efficient nanostructured photocatalysts for solar energy conversion applications.
基金supported by the National Natural Science Foundation of China(Nos.61204033,61331015)the Fundamental Research Funds for the Central Universities(No.WK2100230015)the Funds of Science and Technology on Analog Integrated Circuit Laboratory(No.9140C090111150C09041)
文摘This paper analyzes the power consumption and delay mechanisms of the successive-approximation （SA） logic of a typical asynchronous SAR ADC, and provides strategies to reduce both of them. Following these strategies, a unique direct-pass SA logic is proposed based on a full-swing once-triggered DFF and a self-locking tri-state gate. The unnecessary internal switching power of a typical TSPC DFF, which is commonly used in the SA logic, is avoided. The delay of the ready detector as well as the sequencer is removed from the critical path. A prototype SAR ADC based on the proposed SA logic is fabricated in 130 nm CMOS. It achieves a peak SNDR of 56.3 dB at 1.2 V supply and 65 MS/s sampling rate, and has a total power consumption of 555 μW, while the digital part consumes only 203μW.
