CsPbBr3 nanocrystal for mode-locking Tm-doped fiber laser

CsPbBr3 nanocrystal is used as the saturable absorber(SA) for mode-locking Tm-doped fiber laser in a ring fiber cavity.The modulation depth, saturable intensity, and non-saturable loss of the fabricated SA are 14.1%, 2.5 MW/cm^2,and 5.9%, respectively.In the mode-locking operation, the mode-locked pulse train has a repetition rate of 16.6 MHz with pulse width of 24.2 ps.The laser wavelength is centered at 1992.9 nm with 3-dB spectrum width of 2.5 nm.The maximum output power is 110 mW with slope efficiency of 7.1%.Our experiment shows that CsPbBr3 nanocrystal can be used as an efficient SA in the 2-μm wavelength region.

Structural insights into lithium-deficient type Li-rich layered oxide for high-performance cathode

As one of the promising candidate cathode materials for the high-performance lithium-ion batteries,Li-rich layered oxides still suffer from a series of critical drawbacks,such as voltage decay,oxygen release,irrevers-ible migration of transition metal ions,etc.In this work,Li-deficient method has been confirmed as an effective approach to improve the overall electrochemical performances of Li-rich cathode.The optimized lithium-deficient Li-rich layered cathode exhibits splendid discharge capacity of~297 mAh/g at 0.1 C and prominent rate per-formance of-143 mAh/g at 5 C.Subsequently,neutron diffraction in combination with Raman spectroscopy is applied to explore and clarify the underlying mechanism for improved performances.It was found that the lithium-deficient induced nickel migration and oxygen vacancy play an significant role in improving electro-chemical performances,because migration of nickel into Li layer is able to expand the Li layer spacing and reduce the Li/Ni antisite,leading to facilitated diffusion of lithium ions.Moreover,the formation of oxygen vacancy is able to promote anionic redox processes and suppress the gas release,thus leading to higher capacity.The results present valuable structural insights into the influence of lithium deficiency and provide guidance for the devel-opment of Li-rich cathode materials.

Preparation of hollow-fiber nanofiltration membranes of high performance for effective removal of PFOA and high resistance to BSA fouling

Nanofiltration(NF)process has become one of the most promising technologies to remove micro-organic combined water pollution.Developing a NF membrane material with efficient separation for perfluorooctanoic acid(PFOA)combined pollution is highly desired,this manuscript targets this unmet need specifically.In this work,hydrophilic SiO_(2)nanoparticles with various contents blended with carboxylic multiwalled carbon nanotube were used to modify poly(m-phenylene isophthal amide)(SiO_(2)/CMWCNT/PMIA)hollow fiber NF membrane.The modified membrane with 0.1 wt%SiO_(2)doping exhibits way better fouling resistance with irreversible fouling ratio decreased dramatically from 18.7%to 2.3%,and the recovery rate of water flux increases significantly from 81.2%to 97.7%.The separation experiment results had confirmed that the modified membrane could improve the rejection from 97.2%to 98.6%for perfluorooctanoic acid(PFOA)and its combined pollution with bovine serum albumin(BSA).It is clear that this reported SiO_(2)/CMWCNT/PMIA hollow fiber NF membrane potentially could be applied in water treatment.This research also provides a theoretical basis for efficiently removal of PFOA and its combined pollution by NF membrane.