SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3848-7
Conventional heterogeneous photocatalysts often suffer from insufficient light absorption, rapid charge recombination, and a lack of specific reactive sites for efficient photocatalytic oxidation. To overcome these limitations, we propose a molecular polarization engineering approach utilizing structurally well-defined donor (D)-acceptor (A) covalent triazine frameworks (CTFs). The construction of dipole-induced built-in electric fields within the D-A-structured CTFs enables enhanced exciton dissociation and facilitates directional charge transfer. Specifically, the asymmetric A1-D-A2 moiety enhances molecular polarization in the dual-acceptor system CTF-TBT (A1-D-A2), enabling efficient charge separation through multiple electron-withdrawing units. This structural design promotes directional electron transfer toward the secondary acceptor (benzothiazole, A2), while simultaneously concentrating holes on the donor unit. Consequently, the A2 moiety acts as a site for efficient O2 activation via electron accumulation, whereas the highly oxidized donor unit provides strongly positive holes (h+) that facilitate substrate oxidation. Experimental and DFT calculation results confirm that CTF-TBT demonstrates highly enhanced photocatalytic oxidation performance, which can be attributed to its multi-channel charge separation mechanism and spatially separated redox-active sites. This study highlights the effectiveness of molecular dipole engineering in designing heterogeneous photocatalysts with controlled charge transfer pathways and improved redox capabilities. The proposed design principles provide a universal approach for promoting solar-driven chemical synthesis applications.
Chinese Journal of Environmental Engineering•2026•DOI: 10.12030/j.cjee.202510004
Ammonium salt crystallization-induced blockage of the regenerative heat exchanger in regenerative thermal oxidizers (RTOs) remains a critical operational challenge, particularly in pharmaceutical applications where NH4Cl constitutes up to 70% of the fouling deposits. This study employs computational fluid dynamics (CFD) to systematically simulate six purging configurations, varying injection angle and pipe arrangement, and quantifies purging effectiveness via a novel evaluation method based on characteristic observation planes. Using the Realizable k-ε turbulence model coupled with a porous media model, we analyze the velocity distribution and low-velocity failure zones at the gas chamber–regenerator interface. Results demonstrate that a single-pipe 45° oblique injection achieves the highest effective purging area of 57.6%, a 35.7% improvement over conventional horizontal purging. Increasing pipe diameter significantly enhances flow uniformity, yielding an efficiency gain of approximately 40%, outperforming mere increases in gas velocity. A synergistic optimization strategy is proposed, prioritizing high-performance purging structures with coordinated parameter tuning. The recommended configuration—single-pipe 45° injection, 280 mm pipe diameter, and 14 m·s−1 gas velocity—achieves 88.2% purging efficiency without additional fan power, representing a 45.6% improvement over conventional modes. These findings provide a theoretical basis and engineering solution for RTO purging system design and operational optimization.
Journal of Environmental Engineering Technology•2026•DOI: 10.13205/j.hjgc.202606021
To provide a theoretical basis for energy-saving combustion of regenerative thermal oxidizers (RTOs), this study analyzes energy nodes during RTO operation, refines heat balance accounting, and establishes an overall energy system. Taking a three-chamber RTO as the research object, the enthalpy of exhaust gas at different stages is calculated, and a whole-process heat balance model is developed to systematically analyze exhaust gas preheating, combustion, heat recovery, and heat loss transfer. An improved energy accounting method is proposed to address dynamic heat exchange inside heat accumulators, coupling of multiple gas streams, and boundary heat loss under complex conditions. The longitudinal temperature distribution function of heat accumulators is introduced to overcome difficulties in heat accounting within the accumulator chamber. A thermodynamic system covering 11 key internal energy nodes is constructed. Combined with design characteristics of RTO operation across industries, the application scope of the overall energy system is analyzed; equilibrium terms can be adjusted according to actual conditions, ensuring wide applicability. Validation via an RTO energy system for a glove manufacturing plant demonstrates that outlet temperature prediction accuracy improves from 14.3% to 2.8%, providing a theoretical foundation for future intelligent energy-saving combustion research.