Dimensionality Engineering toward Carbon Materials for Electrochemical CO₂ Reduction: Progress and Prospect

Abstract Carbon materials are of great significance in state‐of‐the‐art electrochemical CO 2 reduction (ECR) as key components such as electrocatalysts, gas diffusion electrodes, and current collectors. Notably, dimensionalities of carbons and related manipulations play vital roles in boosting ECR performance, e.g., mass/charge transfer dynamics, exposure of active sites, reaction space, product's Faradaic efficiency/selectivity, and durability. Here, recent endeavors in dimensionality engineering toward advanced carbon‐based materials for ECR is first summarized, including pure carbons (e.g., carbon nanotube and graphene) and carbon composites, and highlight the dimensionality‐dependent properties toward ECR performance. Various engineering strategies referring to dimensionality modulation and integration have been summarized, e.g., top‐down, bottom‐up, and soft chemical approaches. Design principles of dimensionality‐varied carbons are elaborated, the impacts of dimensionalities of carbons and related surface chemistry (e.g., functional group, wettability, and electronic structure) on ECR kinetics and product‐targeted mechanisms are also scrutinized. Some insights into how the dimensionality manipulation of carbons elevates performance of carbon‐based materials in mass/charge transfer acceleration, ECR kinetics, and product selectivity are provided. At last, a perspective for challenges and future development of dimensionality‐varied carbon materials is discussed. This review aims at providing guidance for customizable construction of carbon materials with dimensionality dependence toward green and energy‐saving electrosynthesis systems.