An, Jin Woo Hyeong, Seok-Ki Kim, Kang Min Lee, Hee Ra Park, Ji-won Kim, Tae-Wook Bae, Sukang Lee, Seoung-Ki 2024-02-07T05:11:08Z 2024-02-07T05:11:08Z 2024-02-07 2024-05 1976-4251 https://pubs.kist.re.kr/handle/201004/148515 In this study, laser-induced graphene oxide (LIGO) was synthesized through a facile liquid-based process involving the introduction of deionized (DI) water onto polyimide (PI) film and subsequent direct laser irradiation using a CO2 laser (lambda = 10.6 mu m). The synthesized LIGO was then evaluated as a sensing material for monitoring changes in humidity levels. The synthesis conditions were optimized by precisely controlling the laser scribing speed, leading to the synthesis of LIGO with different structural characteristics and varying oxygen contents. The increased number of oxygen-containing functional groups contributed to the hydrophilic properties of LIGO, resulting in a superior humidity sensing capabilities compared with laser-induced graphene (LIG). The LIGO-based sensors outperformed LIG-based sensors, demonstrating approximately tenfold higher sensing responsivity when detecting changes at each humidity level, along with 1.25 to 1.75 times faster response/recovery times, making LIGO-based sensors more promising for humidity-monitoring applications. This study demonstrated laser ablation in a renewable and natural precursor as an eco-friendly and energy-efficient approach to directly synthesize LIGO with controllable oxidation levels. English 한국탄소학회 Facile synthesis of laser-induced graphene oxide and its humidity sensing properties Article 10.1007/s42823-023-00672-3 1 Carbon Letters, v.34, no.4, pp.1173 - 1185 Carbon Letters 34 4 1173 1185 N scie scopus kci ART003087312 001152237900001 Chemistry, Multidisciplinary Materials Science, Multidisciplinary Chemistry Materials Science Article SURFACE-AREA WATER Laser-induced graphene oxide Laser scribing speed Humidity sensor Laser-induced grapheme Laser ablation in liquid