Nitrogen‐Enriched Conjugated Polymer Enabled Metal‐Free Carbon Nanozymes with Efficient Oxidase‐Like Activity

Metal‐free carbon nanozymes could be promising with the unique features of intrinsic catalytic ability, structure diversity, and strong tolerance to acidic/alkaline media. However, to date, the study of metal‐free carbon nanozymes fell far behind metal‐based nanomaterials, in which, the majority reported much more peroxidase‐like activity than other enzyme‐mimicking behavior (e.g., oxidase). Thus, the exploit of high‐performance carbon nanozymes is of importance but challenging. In this work, the nitrogen‐rich conjugated polymer (Aza‐CPs) with rigid network structure is utilized as precursor to yield N‐doped carbon material QAU‐Z1 in high yield via a direct pyrolysis method. Surprisingly, QAU‐Z1 stood out in oxidase‐like behavior, which significantly outperformed the control materials GNC‐900 and QAU‐Z2 with nucleobase or conjugated small molecule as precursor, respectively. More importantly, it is a crucial revelation that the catalytic performance is closely related to the change of zeta potential for carbon nanozyme during the substrate 3,3′,5,5′‐tetramethylbenzidine oxidation process, as well as its catalytical capacity to O2, which could be insightful to understand the inherent mechanism. This work not only presents the potential of conjugated polymers in constructing highly efficient carbon nanozyme, but also reveals the vital role of interaction mode between the nanozyme and substrate in the catalytic performance. Nitrogen‐rich conjugated polymer is first utilized as precursor to construct metal‐free N‐doped carbon nanozymes QAU‐Z1, which is almost the best performance among the current metal‐free oxidase‐like nanozymes. The inherent mechanism can be attributed to the zeta potential variation between negative nanozyme and positively‐charged TMB molecules, as well as the capacity of QAU‐Z1 to decrease the overpotential of O2 reduction.