Rational Design of Bimetallic MOF-Derived Cu/Co@N-C Nanocubes for Ultrasensitive Electrochemical Nitrite Detection

en This link goes to a English section zh This link goes to a Chinese section A facile coprecipitation-pyrolysis strategy was employed to fabricate Cu/Co nanoparticles (NPs) embedded in nitrogen-doped carbon matrices (Cu/Co@N-C) through the carbonization of CuCo-MOF precursors. Moreover, monometallic counterparts of Cu@N-C and Co@N-C were also prepared via carbonization of bimetallic CuZn-MOF and CoZn-MOF, respectively. Electrochemical tests confirm that Cu acts as the key active center for nitrite oxidation. By adjusting the Cu/Co molar ratios, a series of cubic Cu/Co@N-C composites with tunable sizes of 200–500 nm were achieved. The synergistic interaction between metallic Cu/Co NPs and the conductive N-C framework enhances catalytic activity and reduces overpotential compared to the monometallic Cu counterpart. The optimized Cu/Co@N-C/glass carbon electrode (GCE) sensor delivered a superior sensitivity as high as 0.461 μA μM −1 cm −2 and wide detection range of 2–10000 μM. The Cu/Co@N-C/GCE sensor also demonstrated superior selectivity, long-term stability of 92.5% retention after 21 days, and reproducibility. This work establishes a versatile approach for engineering various MOF-based catalysts, demonstrating promising potential for applications in environmental monitoring and food safety analysis. 摘要 en This link goes to a English section zh This link goes to a Chinese section 采用一种简便的共沉淀–热解策略 , 以 CuCo-MOF 前驱体为碳源进行碳化 , 成功制备了氮掺杂碳基质负载的 CuCo 双金属纳米颗粒复合材料(Cu/Co@N-C)。此外 , 还分别基于双金属CuZn- MOF和CoZn-MOF碳化制备了Cu@N-C和Co@N-C。电化学测试表明Cu是亚硝酸盐氧化的关键活性中心。通过调控 Cu/Co 摩尔比 , 获得了粒径可调、尺寸范围为 200–500 nm 的立方体 Cu/Co@N-C 复合材料。与单金属Cu@N-C相比 , 金属Cu/Co NPs与导电N-C框架之间的协同作用增强了催化活性并降低了过电位。优化后的 Cu/Co@N-C/玻碳电极(GCE) 传感器表现出优异的电化学传感性能 , 其灵敏度高达 0.461 μA μM −1 cm −2 , 检测范围宽达 2–10000 μM。Cu/Co@N-C/GCE 传感器还展现出优异的选择性、良好的重复性以及长期稳定性 , 在存放21天后仍可保持 92.5% 的电流响应。该工作为构筑各种MOF 基催化材料提供了一种通用策略 , 显示出其在环境监测与食品安全分析领域的广阔应用前景。