Direct Conversion of Folate from Orange Peel into Laser-Induced Graphene and Its Multifunctional Applications

Laser-induced graphene (LIG) has been extensively explored for various applications due to its low cost, simple preparation, and excellent physical and chemical properties. Compared to non-degradable polymers such as polyamide (PI), bio-based precursors offer immense advantages for more sustainable development. In this study, folate was innovatively proposed as the precursor for high-quality LIG synthesis, which was further used for the development of strain sensors and electrochemical catalysis. The folate-based LIG strain sensor demonstrated a broad operating range (0–12%), high sensitivity (with a gauge factor up to 361), exceptional stability, and reliability (exhibiting a consistent response over 10,000 repeated stretching cycles). Moreover, it exhibited precise detection capabilities for subtle deformations induced by human respiration, speech, swallowing, pulse beating, and joint movements. In terms of electrochemical catalysis, folate-based LIG demonstrated a remarkable enhancement in increasing the degradation rate of pollutants like Rhodamine B through the electro-Fenton process. The findings of this study suggest that LIG derived from folate processes shows huge promise for applications such as medical monitoring, micromotion recognition, and water pollutant remediation.