Efficient water disinfection with ball milled Mg-biochar: The key role of trace Cu

In this study, magnesium and coconut shell carbon (CSC) were prepared by a ball milled process and used for water disinfection with adsorbing tiny amounts of copper(II). Dissolved oxygen (DO) was reduced to hydrogen peroxide (H_(2)O_(2)) via a two-electron pathway by Mg corrosion. Cu(II) in the wastewater will be enriched on the CSC surface and efficiently catalyzes H2O2 for inactivating E. coli. The results show that E. coli with an initial concentration of approximately 106 CFU/mL was under the detection limit (<4 CFU/mL) within 15 min. All of the Cu(II) could be adsorbed by the composite and catalyzed H2O2 to different active species. The quenching experiments, electron spin resonance (ESR) capture measurements and the UV-vis spectroscopy detection confirmed the present of the hydroxyl radicals (·OH), superoxide radicals (·O_(2)^(-)) and Cu(III). Different with tradition Fenton like process, Cu(III), rather than radicals, played the major role during the Mg-CSC/Cu(II) process. In addition to the cellular membrane damage, most of the bacterial genomic DNA was also be degraded and the bacterial reactivation was avoided. The Mg-CSC/Cu(II) process also showed a satisfied disinfection performance in real wastewater treatment. Overall, this study provides a new strategy for water disinfection.

Developing near-infrared quantum-dot light-emitting diodes to mimic synaptic plasticity

The quantum-dot light-emitting diodes(QLEDs)that emit near-infrared(NIR)light may be important optoelectronic synaptic devices for the realization of artificial neural networks with complete optoelectronic integration.To improve the performance of NIR QLEDs,we take advantage of their low-energy light emission to explore the use of poly(3-hexylthiophene)(P3 HT)as the hole transport layer(HTL).P3 HT has one of the highest hole mobilities among organic semiconductors and essentially does not absorb NIR light.The usage of P3 HT as the HTL indeed significantly mitigates the imbalance of carrier injection in NIR QLEDs.With the additional incorporation of an interlayer of poly[9,9-bis(3’-(N,N-dimethylamino)propyl)-2,7-flourene]-alt-2,7-(9,9-dioctylfluorene)],P3 HT obviously improves the performance of NIR QLEDs.As electroluminescent synaptic devices,these NIR QLEDs exhibit important synaptic functionalities such as short-and long-term plasticity,and may be employed for image recognition.

Erratum to:Improving near-infrared quantum-dot light-emitting diodes to mimic synaptic plasticity(vol 62,issue 10,page 1470,2019)

In the version of the article originally published in the volume 62,issue 10,2019 of Sci.China Mater,(page 1470-1478,https://doi.org/10.1007/s40843-019-9437-9),wrong images of Figs 3 and 4 were used.The corrected version appears below:the units of the x-axes in Fig.3h,the inset of Fig.4a,and Fig.4b,d should be h,s,s,and s,respectively.