Preparation and applications of nanocellulose and its semiconductor composites: a review

Due to their adjustable electronic properties, strong electromagnetic coupling capability, various nanostructures and other advantages, semiconductor materials have been widely used in various applications in recent years. Semiconductor composite materials can not only expand semiconductors' own advantages but also mitigate the disadvantages of a single material. Natural, plant-based, and biodegradable materials have attracted great interest for generating composite materials. Among them, nanocellulose, an environmentally friendly and biocompatible material that can be obtained from natural bacteria or plants, has been emerging as a promising substrate for energy storage, thermal management, and biomedical sensors, among other areas. Owing to the ultrasmooth surface, flexibility, various surface functional groups and high optical transparency of nanocellulose, nanocellulose-based composite materials can expand the utilization of semiconductors to various fields, including flexible electronics, wearable devices and optical sensing. However, the research summary of the interaction mechanisms between nanomaterials and semiconductors has not yet been reported. This review provides a comprehensive and critical overview of nanocellulose-semiconductor composites, covering three key aspects: the classification and extraction of nanocellulose, a comparative analysis of fabrication methods and their broad applications in photocatalysis, food packaging, and energy storage, among others. This review aims to inspire the rational design and practical translation of nanocellulose-semiconductor composites across diverse technological fields.