氮掺杂水热碳/石墨烯复合膜的制备及其性能研究

Study on preparation and properties of nitrogen-doped hydrothermal carbon/graphene composite films

以废弃柚子皮瓤和氧化石墨烯(GO)为碳源,氨水为掺杂剂,采用水热与真空抽滤相结合的方法,制备氮掺杂石墨烯(N-G)、氮掺杂水热碳膜(N-HC)和氮掺杂水热碳/石墨烯复合膜[N-HC/G-X,X=1、2、4、5,X代表柚子皮瓤(g)与GO(mg)的质量比],利用扫描电镜、X射线衍射、拉曼光谱和红外光谱表征碳材料的物理化学性质,并进行了吸附Zn(Ⅱ)和截留Cr(Ⅵ)的实验。结果表明:N-G、N-HC和N-HC/G-X均为典型片层结构,N-HC是获得薄膜的必要成分,N-HC/G-1和N-HC/G-2的成膜效果优于N-HC/G-4和N-HC/G-5,N-HC/G-1的膜厚度大约为65μm, C、N和O的质量分数分别为65.63%、15.06%和19.31%。N-G、N-HC和N-HC/G-X都是无定形碳材料,N-HC的d002片层间距最大,随着N-HC/G-X中N-G质量的逐渐增多,N-HC/G-X的片层间距逐渐减小,表面缺陷和混乱程度有所增大,且N-HC/G-X表面存在大量的含氧和含氮官能团,可以提供更多活性吸附位点,有利于提升对重金属的吸附效果。N-HC/G-1和N-HC/G-2对Zn(Ⅱ)的吸附效果优于N-HC,N-HC/G-2对Zn(Ⅱ)的吸附率可达79.13%,而N-HC/G-4和N-HC/G-5对Zn(Ⅱ)的吸附效果较N-HC差。N-HC和N-HC/G-X对Cr(Ⅵ)的截留率随复合材料中N-G质量的增多而逐渐增大,水通量则逐渐减小,N-HC/G-5对Cr(Ⅵ)的截留率高达86.45%,水通量为18.20L/(m^(2)·h)。

In this paper,nitrogen-doped graphene(N-G),nitrogen-doped hydrothermal carbon films(N-HC),and nitrogen-doped hydrothermal carbon/graphene composite films(N-HC/G-X,X=1,2,4,5,X represents the mass ratio of pomelo peel pulp(g)to GO(mg))were prepared via a combined hydrothermal and vacuum filtration process using waste pomelo peel pulp and graphene oxide(GO)as carbon sources,as well as ammonia as dopant.The physicochemical properties of N-G,N-HC and N-HC/G-X were characterized by SEM,XRD,Raman and FTIR,and the experiments of Zn(Ⅱ)adsorption and Cr(Ⅵ)retention were also carried out.Research results showed that:N-G,N-HC and N-HC/G-X were all typical lamellar-like structures.N-HC was a necessary component to obtain the thin films.The film-forming effects of N-HC/G-1 and N-HC/G-2 were better than those of N-HC/G-4 and N-HC/G-5.The film thickness of N-HC/G-1 was about 65μm,and the mass percentages of C,N and O were 65.63%,15.06%and 19.31%,respectively.N-G,N-HC and N-HC/G-X samples were all amorphous carbon materials.The d002 lamellar spacing of N-HC was the largest.With the increasing of N-G mass in N-HC/G-X samples,the lamellar spacing of N-HC/G-X decreased gradually,while the degree of surface defects and disorder increased.Furthermore,there were a large number of oxygen-containing and nitrogen-containing functional groups on the surface of N-HC/G-X,which could provide more active adsorption sites and improve the adsorption properties of heavy metals.The adsorption effect of N-HC/G-1 and N-HC/G-2 for Zn(Ⅱ)was better than that of N-HC,and the Zn(Ⅱ)adsorption rate on N-HC/G-2 was 79.13%,while the adsorption effect of N-HC/G-4 and N-HC/G-5 for Zn(Ⅱ)was worse than that of N-HC.The interception rate of N-HC and N-HC/G-X for Cr(Ⅵ)increased gradually with the increasing of N-G mass in the composites,while the water flux decreased gradually.The interception rate of N-HC/G-5 for Cr(Ⅵ)reached 86.45%,and the water flux was 18.20L/(m^(2)·h).