Transition Metal-Decorated Biphenylene Sheet for Dioxin Detection: A First-Principles Investigation

Detecting highly toxic environmental pollutants, such as 2,3,7,8-tetrachlorodibenzo-<i>p</i>-dioxin (TCDD), is crucial for environmental safety. However, current sensors often lack the necessary sensitivity and efficiency for rapid detection and reusability. In this study, we explore the potential of biphenylene (BPh), a 2D carbon allotrope, for TCDD detection by using density functional theory (DFT). To enhance the performance of BPh monolayers, we introduced metal decoration using Sc, Co, and Pd. Our analysis includes geometric structure, adsorption energy, partial density of states (PDOS), charge transfer mechanisms, and work function evaluation. The results reveal that while TCDD weakly adsorbs onto pristine BPh, metal decoration significantly improves the adsorption strength by enhancing charge transfer between TCDD and the BPh monolayer, leading to stronger orbital hybridization and more stable adsorption configurations. The Co-decorated BPh system exhibits the highest adsorption energy at -1.95 eV, followed by Pd (-1.77 eV) and Sc (-1.48 eV), with Co and Pd systems showing strong interactions but limited reusability due to prolonged desorption times. In contrast, the Sc-decorated BPh monolayer balances strong adsorption and efficient desorption, making it the most practical candidate for sensing applications. The recovery time for the Sc-decorated system at 500 K was calculated to be 1.59 s, and under UV light, it reduced to 89.2 ms, indicating optimal desorption efficiency. These findings suggest that Sc-decorated BPh monolayers hold promise for developing practical, reusable sensors for TCDD detection, providing both high sensitivity and reusability.