Monolithic wood biochar as functional material for sustainability

Abstract

AbstractTrees are crucial to humankind's survival, releasing the oxygen we breathe, growing the fruits we eat, and supplying wood to build and warm our shelters. Heating wood at 300°C‐800°C with little or no oxygen creates wood biochar, a carbonaceous product. Wood biochar monoliths have a continuous carbon matrix and morphological features that resemble anatomical elements in a tree, including xylem and phloem, which transport water from the root and deliver sugars from leaves to individual cells. Structurally and chemically, monolithic wood biochar belongs to nanoporous carbons (NPCs) consisting of carbon nanotubes arrays and integrated graphene sheets. Researchers have extensively explored NPCs as functional materials for applications essential to sustainability, including electrical energy storage, water purification, and CO2 capture. However, the lack of scalable manufacturing technology continues to hinder the large‐scale utilization of NPCs despite their demonstrated superiority in enhancing materials performance. Derived from abundant woody biomass with simple processes, wood biochar monoliths offer a new opportunity for overcoming this limitation. This review documents recent progress in applying wood biochar monoliths in areas critical to sustainability, focusing on electrical energy storage and water purification. This progress has revealed the potential of monolith wood biochar as a greener, more cost‐effective, and scalable NPC in enhancing sustainability and opened the door to a new field that is both exciting and relevant. The review concludes with a perspective on the future research direction.