Xiuping Zhu

Cost‐effective chemiresistive gas sensors are widely applicated in the commercial detection of volatile organic compounds (VOCs). However, their poor selectivity towards a target VOC within chemically similar mixtures impedes both qualitative and quantitative accuracy. This arises from the absence of intrinsic chemical criteria for designing selective sensing systems. This research emphasizes the importance of orbital engineering to achieve selectivity in chemiresistive materials. We tailor O 2 p ‐band center (ε _{O‑2 p} ) of the model material SnO ₂ , achieving near 100% selectivity towards triethylamine (C ₆ H ₁₅ N) and exceptional selectivity towards formaldehyde (CH ₂ O), respectively, and maintaining these selectivity performances in gas mixtures. Specifically, tailoring the ε _{O‑2 p} enables energy‐level matching between O 2 p orbitals and frontier molecular orbitals (FMOs) of distinct VOCs gases, thereby inducing selective orbital hybridizations. Such hybridization drives specific adsorption‐reaction processes and provides the electron‐transfer channel, ultimately triggering the exclusive electrical response. These findings not only unveil the origin of sensing selectivity but also establish a chemical coding strategy for the rational design of exclusive gas sensors based on an orbital‐energy‐matching framework.

Cost‐effective chemiresistive gas sensors are widely applicated in the commercial detection of volatile organic compounds (VOCs). However, their poor selectivity towards a target VOC within chemically similar mixtures impedes both qualitative and quantitative accuracy. This arises from the absence of intrinsic chemical criteria for designing selective sensing systems. This research emphasizes the importance of orbital engineering to achieve selectivity in chemiresistive materials. We tailor O 2 p ‐band center (ε _{O‑2 p} ) of the model material SnO ₂ , achieving near 100% selectivity towards triethylamine (C ₆ H ₁₅ N) and exceptional selectivity towards formaldehyde (CH ₂ O), respectively, and maintaining these selectivity performances in gas mixtures. Specifically, tailoring the ε _{O‑2 p} enables energy‐level matching between O 2 p orbitals and frontier molecular orbitals (FMOs) of distinct VOCs gases, thereby inducing selective orbital hybridizations. Such hybridization drives specific adsorption‐reaction processes and provides the electron‐transfer channel, ultimately triggering the exclusive electrical response. These findings not only unveil the origin of sensing selectivity but also establish a chemical coding strategy for the rational design of exclusive gas sensors based on an orbital‐energy‐matching framework.

Electrochemical CO ₂ reduction reaction (CO ₂ RR) offers a promising pathway for converting CO ₂ into value‐added chemicals, contributing to climate change mitigation and the advancement of sustainable chemical production. In CO ₂ RR flow cell systems, developing gas diffusion electrodes (GDEs) with enhanced electrochemical performance is crucial for enabling commercial applications. However, the exploration of copper‐based self‐supported GDEs is constrained by a narrow selection of substrates. 3D printing technology offers an approach to creating intricate structural components, but its integration with GDE fabrication remains unexplored. Here, a 3D‐printed copper‐based GDE, fabricated via fused deposition modeling (FDM) and featuring a tunable porous structure, is successfully applied in a CO ₂ RR flow cell. Under specified operating conditions, adjusting the thickness of the electrode's solid layer influenced H ₂ selectivity, while modifying the thickness or density of the grid‐like infill layer allowed for tuning C ₂ H ₄ and CO selectivity. Notably, the S2I2 electrode configuration, with 0.2 mm‐thick solid and infill layers, achieves 47% C ₂₊ product selectivity at a current density of 200 mA cm ⁻² . This work demonstrates the potential of 3D printing for designing architecture‐tailored GDEs and tuning CO ₂ electroreduction product distributions.

Water scarcity is a growing global challenge. Developing energy-efficient and sustainable desalination methods is crucial to addressing the global water crisis. In recent years, hydrogel-based desalination has emerged as a promising approach due to the excellent water absorption capacity and stimuli-responsive properties of hydrogels. However, conventional dewatering methods for recovering water from hydrogels often suffer from low efficiency and poor stability. To address these challenges, a novel approach using ammonia gas to dewater poly(acrylic acid-co-acrylamide) hydrogels was investigated, achieving significantly higher dewatering rates (up to 110 g_H2O/g_hydrogel/h), among the highest reported, with water production rates ranging from 600 to 1140 L_H2O/kg_hydrogel/day and an average salt rejection of around 60% for both synthetic and real seawater water. The process also demonstrated excellent stability, maintaining a consistent performance over 100 cycles. This technology shows great potential for desalinating brackish water for agricultural irrigation or integration with reverse osmosis systems for seawater desalination, significantly reducing energy consumption and capital costs. This innovative dewatering method could enable practical applications of hydrogel-based desalination.