液氮剥离超薄类石墨相氮化碳的制备及表征

Preparation and Electrochemical Application of Ultra-thin Carbon Nitride

以不同富氮碳源作为前驱体制备块体氮化碳(g-C_(3)N_(4),CN),液氮为剥离溶剂,采用高温-快速气化联合的方法对块体CN g-C_(3)N_(4)进行剥离,制备了超薄CN纳米片,并成功应用于光催化污染物的降解和构建环境激素电化学传感器。经过一系列优化得到制备条件最优的富氮碳源和氮化碳的剥离量,结果显示:不同富氮碳源制备的CN g-C_(3)N_(4)剥离后的比表面积均大大增加,以三聚氰胺为富氮碳源制备的CN g-C_(3)N_(4)片层平均厚度最薄,为1.5 nm。剥离量为1.0 g时剥离效果更佳均匀,比表面积相对较大。与块体CN g-C_(3)N_(4)相比,剥离后的超薄CN比表面积增加了8~12倍,平均片层厚度小于2.8 nm,其原子层数可调,且阻抗均大幅减小。光催化降解罗丹明B(RhB)速率常数较块体CN g-C_(3)N_(4)增加了58倍以上,且对环境雌激素四溴双酚A(TBPPA)有较高的电催化活性。为大规模制备原子层数可调的超薄CN纳米片的工业化应用提供了新的思路。

Bulk carbon nitride(g-C_(3)N_(4),CN)prepared by using different nitrogen-rich carbon sources as precursors,using liquid nitrogen as the stripping solvent,using high temperature-rapid gasification combined method to strip the bulk CN g-C_(3)N_(4)to prepare the ultra-thin CN nanosheets were successfully applied to the degradation of photocatalytic pollutants and the construction of environmental hormone electrochemical sensors.After a series of optimizations,the nitrogen-rich carbon source and carbon nitride stripping amount with the best preparation conditions were obtained,and the results showed that the specific surface area of CN g-C_(3)N_(4)prepared from different nitrogen-rich carbon sources was greatly increased after stripping,and CN g-C_(3)N_(4)prepared with melamine as the nitrogen-rich carbon source the average thickness of CN C_(3)N_(4)lamella is the thinnest,1.5 nm.When the peeling amount is 1.0 g,the peeling effect is better and uniform,and the specific surface area is relatively large.Compared with the bulk CN g-C_(3)N_(4),the specific surface area of the stripped ultra-thin CN increased by 8-12 times,the average sheet thickness was less than 2.8 nm,the number of atomic layers was adjustable,and the impedance was greatly reduced.The rate constant of photocatalytic degradation of RhB is 58 times higher than that of bulk CN g-C_(3)N_(4),and it has obvious electrocatalytic activity for the environmental estrogen tetrabromobisphenol A(TBPPA).This article provides a new idea for the industrial application of large-scale preparation of ultra-thin CN nanosheets with adjustable atomic layers.