Microporous N,P‐Codoped Graphitic Nanosheets as an Efficient Electrocatalyst for Oxygen Reduction in Whole pH Range for Energy Conversion and Biosensing Dissolved Oxygen

Abstract

Microporous N,P-codoped graphitic nanosheets (N,P-CMP-1000) were synthesized by thermal annealing (1000 °C) of as-synthesized conjugated microporous polymers (CMPs) in the presence of phytic acid, which can be used as an effective metal-free electrocatalyst for the oxygen reduction reaction (ORR) for energy conversion. In the whole pH range (i.e. alkaline, acidic, and neutral solutions), the obtained N,P-CMP-1000 exhibits superior electrocatalytic activity for ORR with a low overpotential, high current density, and good stability. Furthermore, N,P-CMP-1000 can also be applied for electrochemically sensing dissolved oxygen (DO), with a high sensitivity (1.89 μA mg L) and broad detection range (2.56 to 16.65 mg L ) due to its good electrocatalytic performance towards ORR in neutral solution. In vitro cytotoxicity tests (CCK-8 and Live/Dead Cell Double Staining Assay) of N,P-CMP-1000 extracts demonstrated its good biocompatibility to Human Corneal Epithelial Cells (HCEC), which shows its great potential as an eye-wearable biosensor for sensing DO in tears.

Phosphate‐Assisted Dispersion of Iron Phosphide in Carbon Nanosheets towards Efficient and Durable ORR Catalysts in Acidic and Alkaline Media

“…[17] The moderate electronegativity of P atoms can draw electrons from metal atoms, subsequently weaken the binding force between metal and adsorbed intermediate species, and finally facilitate the kinetics of ORR. [17,18] Nevertheless, they still cannot meet the requirements of ORR activity and durability, especially in acidic condition.…”

N,P Co‐Coordinated Manganese Atoms in Mesoporous Carbon for Electrochemical Oxygen Reduction

“…Specifically, two main bands at ≈1334 and 1592 cm −1 are detected in the MnNPC‐900, which can be ascribed to the D band induced by defects and G band caused by sp 2 hybridization carbon atoms, respectively . Among them, the ratio of the intensities of D and G band ( I D / I G ) for the MnNPC‐900 (0.88) is higher than that of the MnNC‐900 (0.84), implying that the successful doping of P has induced the high level of structural disorder …”

Carbon Nanomaterials for Energy and Biorelated Catalysis: Recent Advances and Looking Forward

“…182 In vitro cytotoxicity tests (CCK-8 and live/dead cell double staining assay) further demonstrated a high biocompatibility of N,P-CMP-1000 to human corneal epithelial cells (Figure 10d, e), indicating a good promise as an eye-wearable biosensor for detecting DO in tears to monitor eye health (Figure 10f). 182…”

“…More recently, microporous graphitic nanosheets with N,P-codoping (N,P-CMP-1000) were fabricated by the pyrolysis of as-prepared conjugated polymers and phytic acid, which was then employed as highly active C-MFC toward overall ORR in a broad pH range. Specifically, having a high electrocatalytic activity for ORR in neutral solution (Figure c), N,P-CMP-1000 was successfully used for DO electrochemical quantification with a low detection limit of 1.89 μAmg –1 L and wide detection range from 2.56 to 16.65 mg L –1 . In vitro cytotoxicity tests (CCK-8 and live/dead cell double staining assay) further demonstrated a high biocompatibility of N,P-CMP-1000 to human corneal epithelial cells (Figure d, e), indicating a good promise as an eye-wearable biosensor for detecting DO in tears to monitor eye health (Figure f) …”

“…In vitro cytotoxicity of N,P-CMP-1000 extracts against (d) human corneal epithelial cells determined by CCK-8 assay and (e) live/dead cell double staining assay. (f) Schematic of the potential using N,P-CMP-1000 for sensing DO in the wearable glasses to monitor eye health . Images reprinted with permission from refs and .…”