Ling Zhang

Although environmentally benign chemical mechanical polishing (CMP) systems have attracted increasing attention, simultaneously achieving high material removal efficiency, atomic-level surface quality, and low additive concentration remains challenging. In this work, a sustainable silicon CMP slurry was developed by integrating lysine-derived monodisperse SiO ₂ abrasives with the organo-superbase 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and glycine (Gly). Owing to its strong basicity, DBU enables efficient silicon oxidation at substantially reduced additive concentration, while Gly improves slurry stability and interfacial chemical–mechanical interactions. The optimized slurry containing 2.0 wt.% 85 nm SiO ₂ , 0.5 wt.% DBU, and 0.5 wt.% Gly achieved an ultra-smooth silicon surface with a roughness average (Ra) of 0.153 nm and a material removal rate (MRR) of 163.42 nm min ⁻¹ , outperforming a commercial slurry (Ra = 0.953 nm, MRR = 136.82 nm min ⁻¹ ). Electrochemical and spectroscopic analyses revealed that DBU accelerates silicon oxidation, whereas Gly stabilizes the slurry and facilitates favorable interfacial reactions during polishing. The developed slurry provides a promising strategy for sustainable and high-precision silicon CMP.

Selective partial oxidation of methane (CH₄) at room temperature is a challenge in catalytic chemistry. Herein, we report a piezoelectric‐responsive metal‐organic framework (MOF), Cu‐UiO‐66‐NH₂, as an efficient catalyst to convert CH₄ to C1 products selectively. In flow reactors under ultrasonic activation, this catalyst achieves a methanol production rate of 175.1 µmol·g⁻¹·h⁻¹ with 82% selectivity. Parallel experiments in batch reactors demonstrate yields of CO (297.4 µmol·g⁻¹·h⁻¹) and H₂ (140.6 µmol·g⁻¹·h⁻¹). In the piezocatalytic process, in situ generated H₂O₂ was decomposed to produce hydroxyl radical (·OH) to active C─H of CH₄. Cu(II)‐O· species could formed from the decomposition of Cu(II)‐OOH intermediate to selective partial oxidation CH₄ but not to form CO₂. This MOF‐based catalyst design integrated piezocatalysis and mimics enzymatic catalysis, supplying new insight to develop robust catalysts for the industrial conversion of methane with low concentration (<10%).

The direct conversion and efficient utilization of methane pose a critical scientific challenge. Indirect activation via reactive oxygen species (ROS) offers a high probability of contact with methane and conversion efficiency under mild conditions. However, reported product yields are suboptimal due to challenges in activating oxygen and facilitating mass transfer in suspension systems. We propose the use of contact‐electro‐catalysis (CEC), employing polydopamine (PDA) as a catalyst that undergoes electron transfer with oxygen under ultrasound, generating ROS that drives the partial oxidation of methane (POM). Corresponding experimental results indicate that CH₃OH and most HCHO are produced directly from CH₄. Furthermore, through in situ characterizations, we have shown that light pretreatment of the catalysts in an oxygenated atmosphere facilitates the forming of more C=O functional groups with strong electron‐withdrawing properties, thereby significantly enhancing overall product yields, particularly for CH₃OH. Within two hours, product yields reach 1.5 mmol g_cat⁻¹ for HCHO and 0.9 mmol g_cat⁻¹ for CH₃OH. This work introduces a novel approach for efficient POM, while highlighting the distinctive catalytic properties of PDA.