Luminescent Transparent Wood Based on Lignin-Derived Carbon Dots as a Building Material for Dual-Channel, Real-Time, and Visual Detection of Formaldehyde Gas

Abstract

Formaldehyde (FA) is a widespread indoor air pollutant, and its efficient detection is a major industrial challenge. The development of a building material with real-time and visual self-detection of FA gas is highly desirable for meeting both construction and human health demands. Herein, a luminescent transparent wood (LTW) as the building material was developed for dual-channel, real-time, and visual detection of FA gas. It was fabricated by encapsulating multicolor lignin-derived carbon dots (CDs) and poly­(vinyl alcohol) (PVA) into a delignified wood framework. It exhibited 85% optical transmittance, tunable room-temperature phosphorescence (RTP), and ratiometric fluorescence (FL) emission. The tunable luminescence was attributed to different CD graphitization and surface functionalization. The color-responsive ratiometric FL and delayed RTP detections of FA were displayed over the range of 20–1500 μM (R 2 = 0.966, LOD = 1.08 nM) and 20–2000 μM (R 2 = 0.977, LOD = 45.8 nM), respectively. The LTW was also used as an encapsulation film on a UV-emitting InGaN chip to form white light-emitting diodes, indicating the feasibility as an FA-responsive planar light source. The operational notion of functional LTW can expand its applications to new fields such as a stimuli-responsive light-transmitting window or planar light sources while monitoring indoor air pollutants, temperature, and humidity.

Preparation and Applications of Electrospun Optically Transparent Fibrous Membrane

“…For other opaque polymers, chemical treatment and composite modification are needed to obtain transparent products. For example, the optical transparence of natural wood could be significantly improved by the chemical removal of chromogenic groups and lignin, and the penetration of polymers with a suitable refractive index, such as polyvinyl alcohol (PVA) [46,47], epoxy resin [48] and polyimide (PI) [49]. Using epoxy resin as a permeation polymer, Mi et al [50] prepared transparent wood with light transmittance up to 80%, which has a good anti-glare performance and light-guiding properties (as shown in Figure 3).…”

Optical chemosensors for the gas phase detection of aldehydes: mechanism, material design, and application

“…By using the fluorescent CDs, a luminescent transparent wood (LTW) was developed as chemosensor for real-time detection of FA gas in gas phase. 141 phosphorescence sensor response gave a detection limit of 0.6 and 45 ppm, respectively A special kind of CD, graphene quantum dots (GQDs) shave also attracted increasing attention due to the unique electronic and optical properties of graphene intrinsic to the 2D -comjugation.. 142 Wang et al 143 synthesized N-doped graphene quantum dots Unlike the QDs mentioned above, MOFs are unique crystalline porous materials with large specific surface area, tunable pore size and multiple functional groups. MOFs could be self-assembled by coordination bonds between metal (ions or clusters) as nodes and functional organic ligands as supports.…”

Shine-through luminescent wood membranes

“…6,[8][9][10][11][12] Luminescent wood has recently caught considerable attention as an attractive substitute for more conventional materials for indoor and outdoor lighting applications, such as brittle glass and non-biodegradable plastics, thanks to woods sustainability and promising anisotropic optical properties. 7,[13][14][15][16][17] However, state-of-art wood-based lighting appliances require lengthy procedures for their preparation, including delignification and impregnation with often non-biodegradable polymers to improve the matrix transparency, and the use of potentially toxic fluorophores. These approaches compromise the intrinsic sustainability of wood 7,13 as well as native woods' valuable aesthetic appearance, a detail of not negligible importance since it has been demonstrated that the use of natural wood in buildings can have positive effects on the wellbeing of inhabitants.…”