The influence of substrate on the gas sensing performance was studied, focusing on the functional groups of the cellulose substrate. For the study, three different gas sensors were fabricated by spray of Oxidized single-walled carbon nanotubes (Oxy-SWCNTs) on three types of substrates, i.e., silicon wafer, mechanically fibrillated cellulose nanofiber (MFCN), and TEMPO-oxidized cellulose nanofiber (TOCN). The morphologies and chemical structures of the cellulose nanofiber (CNF) substrates were analyzed using electron microscopy and Fourier transform infrared spectroscopy. The surface roughness and the functional group of cellulose substrates gave significant influenced on the sensing performance. The oxygen-containing functional groups of CNFs provided an additional p-doping on the Oxy-SWCNTs, as confirmed by Raman spectroscopy. Especially, TOCN withdrew electrons from the Oxy-SWCNTs owing to the high electron-withdrawing strength of the carboxylate groups. Meanwhile, MFCN had less chance to withdraw electrons because of the weak electron-withdrawing strength of the hydroxy group. As a result, the sensing performances of TOCN-based sensor showed excellent selectivity, sensitivity, and limit of detection toward electron-withdrawing gas, NO₂. Based on the experimental study, a sensing mechanism of CNF-based sensor was proposed in terms of electron transfer pathways.

研究了底物对气敏性能的影响，重点研究了纤维素底物的官能团。在这项研究中，通过在三种类型的基板上喷涂氧化单壁碳纳米管 (Oxy-SWCNT) 来制造三种不同的气体传感器，即硅晶片、机械原纤化纤维素纳米纤维 (MFCN) 和 TEMPO 氧化纤维素纳米纤维 ( TOCN）。使用电子显微镜和傅里叶变换红外光谱分析了纤维素纳米纤维 (CNF) 基板的形态和​​化学结构。纤维素基材的表面粗糙度和官能团对传感性能有显着影响。正如拉曼光谱所证实的那样，CNF 的含氧官能团在 Oxy-SWCNT 上提供了额外的 p 掺杂。尤其，由于羧酸盐基团的高吸电子强度，TOCN 从 Oxy-SWCNT 中吸取电子。同时，由于羟基的吸电子强度较弱，MFCN 吸电子的机会较少。因此，基于 TOCN 的传感器的传感性能显示出对吸电子气体 NO 的出色选择性、灵敏度和检测限₂ . 在实验研究的基础上，从电子传递途径的角度提出了基于 CNF 的传感器的传感机制。