Preparation Of Nano Molybdenum Disulfide By Liquid Exfoliation Of Natural Molybdenite And Its Photoelectric Catalytic Properties

Due to the large energy gap of MoS₂,the MoS₂ with two-dimensional layered structure can make up the disadvantage cased by the absence of band gap of graphene,especially it's unique optical and electrical properties brought by controllablity of energy gap changed with the number of layers,has become a hot research topic in recent years.Large scale production of high-quality single layer or few-layer MoS₂ is the premise of the application.In this paper,exfoliation of natural molybdenite by liquid-phase method to prepare nano MoS₂ was studied.As prepared MoS₂ was characterized and its photoelectric properties were tested.The MoS₂ was applied as a photocatalytic assistant to microbial fuel cell?MFC?.The main research contents are as follows:?1?The natural molybdenite powder were collected from mine field after enrichment and then smashed furtherly,the composition and structure were analyzed.MoS₂ nano particles were obtained by liquid-phase exfoliation using N-methyl pyrrolidone and surfactant P123 aqueous solution in a mild ultrasonic bath.The results show that both the quantum dots and the nano sheets of MoS₂ have been obtained which is highly exfoliated to only several molecular layers.As a comparison,the main products of exfoliated commercial MoS₂ is quantum dots,and the yield is lower than that of molybdenite.?2?MoS₂ nanosheets were obtained from exfoliated molybdenite by isopropanol in ultrasonic bath,but were not obtained from commercial MoS₂ under the same conditions.The effects of different solvents on the subsequent application of products were investigated.The result showed that although the yield of MoS₂ nanosheets exfoliated by isopropanol was reduced,it was convenient for subsequent application.?3?It is suggested that the main mechanism of enhenced efficiency by liquid-phase exfoliation of natural molybdenite probably the impact of quartz phase SiO₂ in minerals.?4?The photoelectric properties of the stripped products of natural molybdenite have been studied.It has been proved that the nano MoS₂ exfoliated from the natural molybdenite has good fluorescence emission and photoconductivity.The modified cathode using exfoliated products can improve the efficiency of MFC due to the large surface area and photoelectric properties of MoS₂ nanosheets.The maximum power density of 118.20mW/m² was obtained under illumination.It was nearly 2 times of that in the blank group under the same condition,and nearly 3 times of that under darkness.