Enabling Lignocellulose-Sourced Feedstocks to Fabricate Optical Filters with Desired Blocking Wavelength.

Near-infrared (NIR) filters have broad applications in fields such as information safety and privacy protection and environmental monitoring. Traditional NIR filters primarily rely on complex optical designs and environmentally unfriendly substrates, while lignocellulose-sourced NIR filters do not achieve the desired blocking wavelength and therefore face challenges in various application conditions. In this study, we propose a thickness adjustment strategy to precisely control the blocking wavelength of the NIR optical filters. The obtained optical filters with tailored thickness exhibited selective blocking wavelength in visible region (400-650 nm) as well as a high NIR transmittance (over 90%) and ultralow haze at 1400 nm. Given their selective wavelength blocking and high NIR transmittance, these bioselectors demonstrate potential applications in NIR optical fields, such as data security and privacy protection, presenting a promising advancement in next-generation sustainable NIR optical materials fabricated from all-lignocellulose feedstocks.