Wenzhong Wang

Graphitic carbon nitride (g‐C ₃ N ₄ ) based semiconductor photoinitiators have attracted considerable interest for photopolymerization. Although structurally engineered g‐C ₃ N ₄ have shown promising photoinitiation performance, how modification‐induced changes in material properties affect their photoinitiation ability remains insufficiently understood. Herein, three g‐C ₃ N ₄ materials prepared through different structural and chemical modification strategies—CN550 (prepared at 550°C), CN700 (thermally exfoliated), and TACN (tartaric acid‐assisted)—are systematically compared as heterogeneous photoinitiators for visible‐light thiol‐ene photopolymerization. The comparative reveals that thermal exfoliation and tartaric acid‐assisted synthesis impart distinct advantages to g‐C ₃ N ₄ photoinitiators. CN700 exhibits consistently high photoinitiation ability across 405–530 nm irradiation, benefiting from improved surface accessibility coupled with favorable optical and electronic properties, while TACN shows improved performance under longer‐wavelength irradiation due to its enhanced light‐harvesting capability. Efficient thiol‐ene photopolymerization is achieved in both organic and aqueous systems without additional co‐initiators, enabling one‐pot fabrication of composite materials. The optimized aqueous formulation is further explored to fabricate conductive hydrogels through NaCl incorporation, while the organic formulation enables direct laser writing for customized patterning. This work demonstrates that the photoinitiation ability of g‐C ₃ N ₄ relies on the combined effects of structural accessibility and photophysical properties, providing guidance for the design of semiconductor photoinitiators for visible‐light thiol–ene photopolymerization.

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.

The selective oxidation of biomass‐derived 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), a key monomer for degradable plastics, is crucial for biomass valorization and addressing plastic pollution. However, its efficiency is limited by high energy barriers and slow kinetics due to the complex multi‐electron and multi‐proton transfer steps. Herein, a MIL‐100(Fe)/TEMPO/nitric acid catalyst system is developed to facilitate electron transfer in HMF oxidation. The catalyst system achieves 100% conversion of 3 wt% HMF in 16 h at 353 K and atmospheric pressure, with a 94% yield of total acid product. The cyclic voltammetry and in situ electron paramagnetic resonance (EPR) reveal that nitric acid promotes TEMPO oxidation to TEMPO ⁺ , facilitating electron transfer and increasing the oxidation rate. The Griess method, ferrocene cation probe, and in situ EPR confirm nitric oxide (NO) formation, which acts as an electron shuttle between oxygen and MIL‐100(Fe), accelerating the Fe(III)/Fe(II) redox cycle. Hydrogen/deuterium kinetic isotope effect analysis supports a proton‐coupled electron transfer (PCET) mechanism. This study demonstrates that nitric acid significantly enhances PCET, enabling rapid oxidation of HMF to FDCA under mild conditions.