Fabrication of Porous Heteroatom-Doped Carbon Networks via Polymer-Assisted Rapid Thermal Annealing

Porous carbon materials have increasingly drawn interest for applications ranging from supercapacitive energy storage to bioengineering. However, a simple and scalable fabrication process of such materials, employing low-cost chemical compounds without sacrificing morphological and chemical control, remains lacking. Here, a novel, rapid, continuous bottom-up strategy for synthesizing structurally tunable porous carbon network films on insulating and conductive substrates is reported. By employing rapid thermal annealing (RTA) of a commercial polyacrylonitrile-based blend, simultaneous phase separation and thermal crosslinking are induced, effectively freezing the structure. Subsequent burning of degradable components generates a porous carbon framework (d over bar pore${\bar{d}}_{{\mathrm{pore}}}$ approximate to 360 to 700 nm) doped with nitrogen and oxygen atoms. Introducing a boron-containing reagent in the precursor solution enables boron doping and pore size reduction as small as 20 nm, enhancing materials' performance. The direct fabrication of micro-supercapacitors on stainless steel substrates is demonstrated, achieving an areal capacitance of 12.7 mF cm-2 at 50 mV s-1, with approximate to 98% retention after 10 000 charge/discharge cycles. The benefit of boron doping is further highlighted for wound healing applications. Because RTA is already an established industrial method, this platform directly facilitates the synthesis of functional porous heteroatom-doped carbon structures using commercial polymers and dopants for various applications. Freeze-burn 2.0 is introduced as a simple bottom-up strategy based on rapid thermal annealing to synthesize heteroatom-doped porous carbon in >= 20 min. A commercial polyacrylonitrile-based blend is employed as both a carbon source and template. The addition of boronic compounds to the precursor formulation permits extrinsic doping and morphological control, enhancing the materials' performance for supercapacitive and wound healing applications.image