Antimony (Sb) has been considered a promising anode for sodium-ion batteries (SIBs) owing to its high theoretical capacity (660 mA h g–1) and low redox voltage (0.2–0.9 V vs Na+/Na). However, the capacity degradation caused by the volumetric variation during battery discharge/charge hinders the practical application. Herein, guided by the DFT calculation, Sb/Fe2S3 was fabricated by annealing Fe and Sb2S3 mixed powder. Next, Sb/Fe2S3 was blended with 15 wt % graphite by ball milling, yielding nano-Sb/Fe2S3 anchored on an exfoliated graphite composite (denoted as Sb/Fe2S3-15%). When applied as an anode of SIBs, Sb/Fe2S3-15% delivered reversible capacities of 565, 542, 467, 366, 285, and 236 mA h g–1 at current rates of 1, 2, 4, 6, 8, and 10 A g–1, respectively, surpassing most of the Sb-based anodes. The co-existence of highly conductive Fe2S3 and Sb minimizes the polarization of the anode. Our experiments proved that the Sb and Fe2S3 phases were reversible during discharge/charge cycling, and the exfoliated graphite can accelerate the Na+ diffusion and e– conduction. The proposed synthesis method of this work can also be applicable to synthesize various antimony/transition metal sulfide heterostructures (Sb/M1–xS), which may be applied in a series of fields.
A new core-shell structure CdS@Fe 2 S 3 material was synthesized by in situ cation exchange method to enhance the degradation of organic pollutants in water under visible light. It is proved that Fe 2 S 3 nanolayer is successfully loaded on CdS nanorods by TEM and UV-Vis spectra and other means. The representative Rhodamine B was selected as the target pollutant and the results of degradation experiment showed that after 60 min of exposure to LED visible light with a low energy (25 W), the removal efficiency for this dye could reach 98 % in the presence of peroxymonosulfate (PMS) forming free radicals, which displayed a observed kinetic rate constant exceeding 0.62 min −1 that is approximately 5 times higher than the system without PMS addition and 10 times than the system with original CdS as catalyst. The result of inhibition experiments shows that sulfate radical (SO 4 ·- ) and singlet oxygen ( 1 O 2 ) play as important roles during the photocatalytic process. In addition, this core-shell material can be recycled at least four times. Generally, this study can make full use of visible light which can be easily obtained and effectually resolve the organic pollution problems.