Laser-Patterned Porous Carbon/ZnO Nanostructure Composites for Selective Room-Temperature Sensing of Volatile Organic Compounds

Abstract

The development of mobile, noninvasive, and portable sensor technologies for diagnostics and emission control is highly demanded. For that purpose, laser carbonization is studied as a tool to produce responsive carbon materials from inexpensive organic precursors for the room-temperature selective detection of volatile organic compounds (VOCs) applicable in future sensor array-based devices. To increase the response of intrinsically low-responsive laser-patterned carbons (LP-C) to analytes in the gas phase, we tested carbonization in the presence of nanoscale ZnO precursors in primary inks. Following the addition of a zinc salt, Zn­(NO3)2, a noticeable 43-fold increase in the sensor response (ΔR/R 0 = −21.5% toward 2.5% acetone) was achieved. This effect is explained by a significant increase in the measurable surface area up to ∼700 m2·g–1 due to the carbothermic reduction supported by the in situ formation of ZnO nanoparticles. Varying Zn concentrations or the addition of as-prepared ZnO nanorods lead to different surface properties like the surface area, porosity, and polarity of LP-C. A predominant effect of the surface polarity on the selectivity toward different analytes of the sensors during physisorption, e.g., acetone vs toluene, was identified and tested. The best-performing LP-C sensors were finely characterized by transmission/scanning electron microscopies and X-ray photoelectron/energy-dispersive X-ray/Raman spectroscopies.

Laser‐Carbonization – A Powerful Tool for Micro‐Fabrication of Patterned Electronic Carbons

“…Polyethylene terephthalate (PET) as a substrate melts at the interface and merges into the LP-C, which supports the stability of flexible electronics. [174] 3.3. Applications -Sensors, Energy Storage, Electrocatalysis, Antennas -Literature review…”

“…Polyethylene terephthalate (PET) as a substrate melts at the interface and merges into the LP‐C, which supports the stability of flexible electronics. [ 174 ]…”

“…A hard-templating effect based on carbothermic reduction of ZnO was utilized for increasing the microporosity of LP-Cs. [39,174] Nanoparticle impregnation or functionalization can be simply achieved by the addition of respective metal salts to the primary inks. For example, LP-C was decorated or impregnated with iron oxide or metallic molybdenum carbide nanoparticles.…”

Sustainable design of high-performance multifunctional carbon electrodes by one-step laser carbonization for supercapacitors and dopamine sensors

“…Various, mostly polymeric starting materials have been used for laser carbonization, such as polyimide (PI), [13][14][15] graphene oxide (GO), 16,17 polyacrylonitrile (PAN) fiber mats, 18,19 or pre-carbonized molecular precursors. [20][21][22][23][24][25] The porous nature and rich functionality of LP-C allows it to be effectively used in applications such as supercapacitors, electrocatalysis, and sensors. 14,17,18,21,[23][24][25][26] However, in many of the previous cases, heavily pre-processed or unsustainable precursor materials have been used for the laser-carbonization.…”

“…[20][21][22][23][24][25] The porous nature and rich functionality of LP-C allows it to be effectively used in applications such as supercapacitors, electrocatalysis, and sensors. 14,17,18,21,[23][24][25][26] However, in many of the previous cases, heavily pre-processed or unsustainable precursor materials have been used for the laser-carbonization.…”