Metal clusters or even single-atoms dispersed and anchored on the photocatalysts'surface can enhance photocatalytic performances on organic pollutant oxidation.Here,a simple photoreduction method was used to creat...Metal clusters or even single-atoms dispersed and anchored on the photocatalysts'surface can enhance photocatalytic performances on organic pollutant oxidation.Here,a simple photoreduction method was used to create atomically dispersed metal single-atoms/clusters(MSCs,M=Cu,Pd,Au and Ag)on P-modulated tubular carbon nitride(TCN).The obtained MSCs@TCN demonstrated excellent photocatalytic performances for the degradation of sulfamethazine(SMZ).In particular,the photocatalyst with 2 wt%Cu loading showed ultrahigh SMZ oxidation efficiency(k=0.06110 min^(-1)),almost three times that of TCN(k=0.02066 min^(-1)).It also shows excellent stability in the 5th-cycle measurements.The improved photocatalytic activity of the CuSCs@TCN is ascribed to the synergistic promotion of photogenerated charge separation by Cu single-atoms/clusters as active sites,accelerated charge transfer from bulk TCN to Cu sites through Cu-N_(x)interaction.Meanwhile,the active sites of Cu single-atoms/clusters could promote the production of·O_(2)^(-),which participates in organic oxidation with strong oxidizing holes(h^(+)).This strategy paves a new avenue for designing high-performance photocatalysts decorated with metal single-atoms and clusters.展开更多
The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocit...The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocity signals in the turbulent boundary layer were measured by HWA. The drag reduction rate of 16.7% is obtained comparable to that of the open-loop control and saves 75% of the input energy at the asynchronous 100 V/160 Hz control case, which reflects the advantages of the closed-loop control. The experimental findings indicate that the intensity increases in the near-wall region.The perturbation of the PZT vibrators on the skewness factor is concentrated in the region y+< 60. The generation of highspeed fluids is depressed and the downward effect of high-speed fluids weakens. The alteration of energy distribution and the discernible impact of modulation between structures of varying scales are observed. The correlation coefficient exhibits a strong positive correlation, which indicates that the large-scale structures produce modulation effect on small-scale ones.The occurrence of burst events is effectively suppressed. The disturbance has the characteristics of stable periodicity,positive and negative symmetry, low intermittency, and high pulsation strength. The conditional phase waveform shows that the fluctuation amplitude increases, indicating amplitude modulation effects on coherent structures.展开更多
基金financially supported by the National Natural Science Foundation of China(No.U22B20102)Shandong Provincial Natural Science Foundation(No.ZR2023QE218)+3 种基金the Young Taishan Scholars Program of Shandong Province(No.tsqn201909026)Taishan Scholars Project of Shandong Province(No.tstp20230604)the Future Young Scholars Program of Shandong University(No.61440089964189)the Key Laboratory of Organic Compound Pollution Control Engineering(MOE)Foundation(No.20190202)。
文摘Metal clusters or even single-atoms dispersed and anchored on the photocatalysts'surface can enhance photocatalytic performances on organic pollutant oxidation.Here,a simple photoreduction method was used to create atomically dispersed metal single-atoms/clusters(MSCs,M=Cu,Pd,Au and Ag)on P-modulated tubular carbon nitride(TCN).The obtained MSCs@TCN demonstrated excellent photocatalytic performances for the degradation of sulfamethazine(SMZ).In particular,the photocatalyst with 2 wt%Cu loading showed ultrahigh SMZ oxidation efficiency(k=0.06110 min^(-1)),almost three times that of TCN(k=0.02066 min^(-1)).It also shows excellent stability in the 5th-cycle measurements.The improved photocatalytic activity of the CuSCs@TCN is ascribed to the synergistic promotion of photogenerated charge separation by Cu single-atoms/clusters as active sites,accelerated charge transfer from bulk TCN to Cu sites through Cu-N_(x)interaction.Meanwhile,the active sites of Cu single-atoms/clusters could promote the production of·O_(2)^(-),which participates in organic oxidation with strong oxidizing holes(h^(+)).This strategy paves a new avenue for designing high-performance photocatalysts decorated with metal single-atoms and clusters.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12202309,1233000165,12172242,and 12272265)Science and Technology Program of Gansu Province of China(Grant No.22JR5RA304)Tianjin Research Innovation for Postgraduate Students(Grant No.22KJ049)。
文摘The experimental research on zero-net-mass-flux jet closed-loop active control was conducted in the wind tunnel.The mu-level method successfully detected burst events of the coherent structures. The streamwise velocity signals in the turbulent boundary layer were measured by HWA. The drag reduction rate of 16.7% is obtained comparable to that of the open-loop control and saves 75% of the input energy at the asynchronous 100 V/160 Hz control case, which reflects the advantages of the closed-loop control. The experimental findings indicate that the intensity increases in the near-wall region.The perturbation of the PZT vibrators on the skewness factor is concentrated in the region y+< 60. The generation of highspeed fluids is depressed and the downward effect of high-speed fluids weakens. The alteration of energy distribution and the discernible impact of modulation between structures of varying scales are observed. The correlation coefficient exhibits a strong positive correlation, which indicates that the large-scale structures produce modulation effect on small-scale ones.The occurrence of burst events is effectively suppressed. The disturbance has the characteristics of stable periodicity,positive and negative symmetry, low intermittency, and high pulsation strength. The conditional phase waveform shows that the fluctuation amplitude increases, indicating amplitude modulation effects on coherent structures.
基金The National Natural Science Foundation of China(Nos.61475127,61575163,61775184,61805205)the Fundamental Research Funds for the Central Universities(No.XDJK2018C079)+1 种基金the China Postdoctoral Science Foundation(No.2018M633303)the Doctor Fund from Southwest University(No.SWU110645)
