吝美霞,李法云,王玮,程文远,周纯亮.生物炭负载P掺杂g-C3N4复合光催化剂制备及其对萘光催化降解机制[J].环境科学学报,2021,41(8):3200-3210
生物炭负载P掺杂g-C3N4复合光催化剂制备及其对萘光催化降解机制
- Synthesis of biochar-supported P-doped g-C3N4 photocatalyst and its photocatalytic degradation mechanism to naphthalene
- 基金项目：国家重点研发计划（No.2020YFC1808802）；国家自然科学基金（No.41571464）；上海应用技术大学协同创新基金（No.XTCX2019-13）；上海高校青年教师培养资助计划（No.ZZyyx19010）
- 吝美霞
- 1. 上海应用技术大学生态技术与工程学院, 上海 201418;2. 湖南农业大学资源环境学院, 长沙 410128
- 李法云
- 1. 上海应用技术大学生态技术与工程学院, 上海 201418;2. 上海城市路域生态工程技术研究中心, 上海 201418
- 王玮
- 1. 上海应用技术大学生态技术与工程学院, 上海 201418;2. 上海城市路域生态工程技术研究中心, 上海 201418
- 周纯亮
- 1. 上海应用技术大学生态技术与工程学院, 上海 201418;2. 上海城市路域生态工程技术研究中心, 上海 201418
- 摘要：采用农业资源废弃物玉米秸秆为生物质原材料，双氰胺为前驱物，（NH4）2HPO4为磷源，通过高温煅烧和浸渍法成功制备了可循环使用的生物炭负载P掺杂g-C3N4复合光催化剂，并采用X射线衍射（XRD）、红外光谱（FTIR）、扫描电子显微镜（SEM）、紫外可见漫反射（UV-vis DRS）和光致发光光谱（PL）等手段对所制备样品的化学结构、表观形貌和光学特性进行了表征.结果表明，成功将P元素引入g-C3N4结构中，可有效改变其能带结构，降低其光生载流子复合几率；此外，生物炭作为载体，具有较好的稳定性和特殊的光电性能，不仅有利于g-C3N4的光电荷分离，还可提高其对可见光的响应能力.选取多环芳烃萘作为研究对象来探究不同种类光催化剂的光催化性能及对萘的去除效率.结果表明，质量比为1：1的生物炭负载P掺杂g-C3N4对萘表现出了最优的光催化性能，去除率为76.41%，一级动力学反应速率常数为0.0084 min-1，是纯g-C3N4的3.1倍.此外，通过自由基捕获实验提出了光催化降解萘的可能机理.
- Abstract：Using agricultural waste biomass corn stover as the raw material, dicyandiamide as the precursor, and (NH4)2HPO4 as the phosphorus source, a recyclable biochar-supported P-doped g-C3N4 composite photocatalyst was successfully prepared through high-temperature calcination and impregnation methods. The crystal structure, apparent morphology, functional group composition and optical properties of the as-prepared photocatalytic materials were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscope (FTIR), UV-vis diffuse reflectance spectra (UV-vis DRS) and photoluminescence technique (PL). The results show that the successful introduction of P element into g-C3N4 can effectively change its energy band structure and reduce its photo-generated carrier recombination probability; In addition, as a carrier, biochar has high stability and special photoelectric properties, not only it is beneficial to the photo-charge separation of g-C3N4, but also it improves the response to visible light. The photocatalytic performance of polycyclic aromatic hydrocarbon naphthalene was explored with different types of photocatalysts. The results showed that the biochar-supported P-doped g-C3N4 with a mass ratio of 1：1 had the best photocatalytic performance for naphthalene, reaching a removal rate of 76.41%, and the first-order kinetic reaction rate constant was 0.0084 min-1, which is 3.1 times that of pure g-C3N4. In addition, a possible mechanism of photocatalytic degradation of naphthalene was proposed through free radical capture experiments.
