Selenium-Doped Amorphous Black Phosphorus@TiO₂/C Heterostructures for High-Performance Li/Na/K Ion Batteries

Abstract

Heterostructures have been confirmed to demonstrate better electrochemical performance than their individual building blocks, which is not only attributed to the complementary advantages of diverse materials but also to various synergistic effects, such as increased active sites at the heterointerfaces, enhanced kinetics from a built-in electric field, stable structure due to physical or chemical bonding, etc. However, constructing a desired heterostructure remains greatly challenging owing to the mismatch of crystal structures, atomic spacings, and reaction mechanisms between different electrode materials. In this study, an amorphous heterostructure composed of Se-doped black phosphorus and metal–organic framework (MOF)-derived TiO2/C (Se-BP@TiO2/C) was successfully fabricated using a simple Se-assisted ball-milling method. In addition to the inherent advantages of heterostructures, the novel material also had considerable free volume in the amorphous domains, which not only buffered the volume change of active materials during cycles but also provided space and interconnected channels for ion diffusion. When used as anode materials for Li/Na/K ion batteries, the Se-BP@TiO2/C achieved high specific capacities, good cyclability, and fast rate capability. This work opens up a new route to design amorphous heterostructure electrodes for high-performance battery systems.

Engineering Support and Distribution of Palladium and Tin on MXene with Modulation of the d‐Band Center for CO‐resilient Methanol Oxidation

“…Thereby, the boosted electron interaction between metal and MXene via Se‐doping progress and the significant charge transfer between Pd and Sn caused by optimized distribution of Pd and Sn sites might enhance the adsorption of CH 3 OH intermediates and further facilitate the initial activation of CH 3 OH, contributing to the improvement of electrocatalytic activity. Figure 2c shows a high‐resolution XPS characterization of Se 3d, in which two peaks at around 55.4 eV, and 56.5 eV correspond to Se 3d 5/2 , and Se 3d 3/2 , respectively, which are well in agreement with the data reported in the literature [19] . The ratio of Se content in PdSn 0.5 /Se−Ti 3 C 2 is 5.33 at%, which is similar to other Pd‐based catalysts in Se−Ti 3 C 2 (Table S2).…”

Amorphous MoO2/C Nanospheres–Porous Graphene Composites for Pseudocapacitive Li Storage

“…They attributed the abnormal Li storage of amorphous MoO 2 to abundant structural defects. In addition, amorphous nanostructures have larger free volumes and loose structures, which are beneficial for fast charge storage. , The above findings suggest that amorphous MoO 2 nanostructures have greater potential than their crystalline counterparts. However, the poor electrical conductivity of amorphous materials limits their use as anodes for LIBs.…”

Harnessing the Defects at Hetero‐Interface of Transition Metal Compounds for Advanced Charge Storage: A Review

“…Reproduced with permission. [172] Copyright 2022, American Chemical Society. composed of selenium-doped black phosphorus (BP) and TiO 2 (Se-BP@TiO 2 /C) by a selenium-assisted ball milling method, the synthesis process is schematically represented by Figure 11d.…”

“…Analogously, Xu and his coworkers synthesized an amorphous heterostructure composed of selenium‐doped black phosphorus (BP) and TiO 2 (Se‐BP@TiO 2 /C) by a selenium‐assisted ball milling method, the synthesis process is schematically represented by Figure 11d. [ 172 ] Ball milling with the addition of Se induces the amorphization of BP and TiO 2 which promotes the formation of chemical bonds such as P – O –Ti at the hetero‐interface of BP and TiO 2 . This allows Se‐BP@TiO 2 /C to suppress the volume expansion of the material during electrochemical cycling and to provide ion diffusion channels in addition to the advantages of the heterostructure itself.…”

“…d) Schematic diagram of the synthesis process of Se-BP@TiO 2 /C heterostructures by the Se doping ball milling method. Reproduced with permission [172]. Copyright 2022, American Chemical Society.…”