TY  - JOUR
AU  - Xu, Jie
AU  - Xu, Jiajun
AU  - Xu, Shiai
AU  - Li, Rujie
AU  - Sun, Beibei
AU  - Wang, Zhongbiao
AU  - Cheng, Jiaxu
AU  - Chai, Kesong
AU  - Zhang, Chao
PY  - 2026
TI  - Morphology transition engineering on MgO for enhanced dye adsorption without using surfactants as sacrifice templates
JO  - Journal of Magnesium and Alloys
SN  - 2213-9567
VL  - 14
IS  - C
AB  - Hierarchical porous MgO is a promising adsorbent for dye removal because of its large Brunauer–Emmett–Teller specific surface area (SBET) and abundant low-coordinated oxygen anions (LCO) sites. As hierarchical porous MgO particles with large SBET values are typically prepared by complicated procedures under harsh conditions, such as high temperatures and high pressures, their large-scale production is impractical. Consequently, the preparation of hierarchical porous MgO with a large SBET value under mild conditions is highly desirable. In this study, a morphology transition engineering strategy is introduced to change the morphology of simple MgO microspheres to an embroidered ball-shaped with a larger SBET value via hydrolysis and calcination without using surfactants as sacrificial templates. During hydrolysis, numerous Mg(OH)2 sheets form and attach to the MgO surface, thus increasing the SBET value of the newly obtained MgO that forms by calcination (denoted as NM-x, where x is the hydrolysis time in hours). The sizes of the crystalline sheets were tuned by controlling the hydrolysis time. NM-12 exhibited the highest density of small-sized sheets on its surface and the largest SBET value of 180.17 m2 g−1, which was 3.51 times that of the MgO precursor (51.89 m2 g−1). However, NM-24 (134.07 m2 g−1) had a higher adsorption efficiency for Congo red (CR) than NM-12, despite having a smaller SBET value, which indicates that other factors are involved. NM-24 exhibited a lower probability of exposed (200) and (220) facets which were verified to repulse CR molecules by molecular dynamics simulations, and a greater number of LCO sites, which contributed to adsorption. Thus, this study introduces a facile method for preparing hierarchical porous MgO and examines the effects of LCO sites and exposed facet probabilities on its adsorption properties.
UR  - https://doi.org/10.1016/j.jma.2025.02.019
DO  - 10.1016/j.jma.2025.02.019