以含铬革屑为原料石墨烯量子点的制备及其在荧光防伪皮革中的研究

A large amount of chromed leather scraps will be produced in leather making processes. It will cause environment pollution by both long-term stack and the release of chromium-containing materials. In addition, the development of leather industry is also restricted by the fake products. In this research, these two problems will be solved by one step. Chromed leather scraps are used as raw materials to prepare graphene quantum dots (GQDs) which will be applied in leather finishing processes. Thus, Cr6+ will be inhibited by the electrons and holes of GQDs. And the leather products can be anti-fake by utilizing the fluorescence property of GQDs. Furthermore, the additional value of leather products is increased, and the pollution of leather waste scraps is prevented simultaneously. The main research includes: the element and amino acid contents are analyzed via analytical instrument at first for the basis of GDQs structure analysis and preparation. Then, GQDs are prepared by hydrothermal reaction of leather scraps. The fluorescence properties of GQDs, chromium form on GQDs and its transformation mechanism will be studied. Finally, fluorescent falsification-preventing leather products will be manufactured and properties will be tested. In this research, GQDs can be low-coat prepared. Meanwhile, the problems of leather scraps pollution and fake leather products can be solved. This research is of great value and has splendid future for socioeconomic and environmental benefits.

皮革加工过程中会产生大量含铬革屑，长期堆放及含铬物质的释放会造成严重的环境污染问题，该问题与仿冒伪造问题严重制约着皮革行业的发展。本项目拟对含铬革屑资源化利用，即以含铬革屑为原料制备石墨烯量子点（Graphene Quantum Dots，GQDs），利用GQDs产生的电子空穴抑制六价铬，并将GQDs用于皮革的涂饰中，通过GQDs的荧光特性，实现对皮革的防伪处理，最终使革屑污染和皮革防伪同时解决。主要研究内容包括：通过氨基酸分析和元素分析确定革屑的氨基酸和元素组成，为GQDs的制备及结构分析提供基础；采用水热法，以革屑为原料制备GQDs，对GQDs的光学性能、铬元素在GQDs中的存在形态及转化机理等进行研究；制造具有荧光防伪性能的皮革制品并对其防伪性能进行检测。本项目可实现GQDs的低成本化制备，并解决含铬革屑的污染问题和皮革防伪问题，具有良好的研究价值和社会环境效益。

皮革加工产生了大量废弃革屑，长期堆放及含铬物质的释放会造成严重的环境污染，该问题与仿冒伪造问题严重制约着皮革行业的发展，将两者协同解决有利于制革行业的可持续发展。本项目首先对含铬革屑资源化利用，即以胶原模拟物明胶、无铬革屑和含铬革屑为原料，采用水热法制备了六种石墨烯量子点（GQDs），考察了其在不同光源下对六价铬的还原性能，结果表明各类GQDs均对Cr(VI)有光催化还原活性，且对Cr(VI)的光催化还原活性具有如下关系：无铬革屑基石墨烯量子点﹥含铬革屑基石墨烯量子点﹥明胶基石墨烯量子点；在334 nm的紫外光照射下，酸皮和灰皮基GQDs对0.1 wt%的Cr(VI)最大还原率分别为100%、97.0%；在模拟日光照射下的最大还原率均为100%。主要原因是两类量子点的导带能量分别为-0.66 eV和-0.65 eV，远低于标准氢电极（NHE）的电势1.05 eV和O2/•O2-的电势-0.33 eV。其次，本项目以废弃革屑为碳源，以对苯二胺和邻苯二胺为氮掺杂源，制备了三原色碳点（红色荧光碳点（R-CDs），绿色荧光碳点（G-CDs）和蓝色荧光碳点（B-CDs）），变色机理的表征和分析表明发射波长的不同主要是由于碳点的碳化程度、官能团的变化等因素引起的。分别以废弃革屑、2-氨基对苯二甲酸和磷酸为前驱体，制备了酸性响应型碳点（L-CDs）和碱性响应型碳点（H-CDs），在酸性物质的作用下，发射波长由457 nm变为633 nm，荧光颜色由蓝色变为红色；在碱性物质的作用下，发射波长由549 nm变为424 nm，荧光颜色由黄绿色变为蓝紫色；这主要是碳点的官能团变化等因素引起的。以革屑和硼酸为原料制备了具有较长余辉的CDs基磷光材料，发射波长为520 nm，具有明亮的绿色余辉，且具有12 s的超长磷光寿命。最后，将不同的碳点用于皮革的防伪处理，同步实现了废弃革屑的资源化利用和皮革的防伪。相关研究也应用至造纸和纺织品的防伪处理。