Zhijie Zhang

Novel Ti _1-x Fe _x O ₂ pigments ( x =   0-0.2) were successfully synthesized via the sol-gel method. Fe³⁺ doping preserved the rutile phase structure of TiO ₂ while suppressing crystal growth; as the Fe content increased, the color of the pigments gradually transitioned from light red to deep red and further to reddish-brown. Among them, Ti _0.9 Fe _{0. 1} O ₂ calcined at 700 ℃ exhibited the optimal red hue ( a * =   25.7), while Ti _0.95 Fe _{0. 0 5} O ₂ treated at 800 ℃ demonstrated the best near-infrared reflectance performance (73.62 %). All samples showed notably higher reflectance in the NIR range compared to a commercial iron-oxide pigment of similar color (44.25 %). Furthermore, chromatic property tests after acid/alkali corrosion, together with thermogravimetric-differential scanning calorimetry analysis, confirmed the good chemical and thermal stability of this series of pigments. These energy-saving pigments show promising potential for application in high-efficiency energy-efficient building materials such as solar heat-reflective functional artificial stones.

Manganese dioxide (MnO ₂ ), as a promising electrocatalyst for the oxygen evolution reaction (OER), is limited in practical application by its poor electrical conductivity and insufficient exposure of active sites. In this study, a boron (B) doping strategy is proposed, in which ammonium pentaborate tetrahydrate (NH ₄ B ₅ O ₈ ·4H ₂ O) is introduced during a hydrothermal process to synthesize α‐MnO ₂ with a nanoneedle‐like structure rich in oxygen vacancies (O _V ) and Mn ³⁺ content. Systematic characterization combined with density functional theory calculations reveals that B doping not only induces a crystal‐phase transition from β‐MnO ₂ to α‐MnO ₂ possessing a large‐tunnel structure, accompanied by the formation of a high‐surface‐area nanoneedle morphology, but also promotes the generation of O _V and significantly increases the Mn ³⁺ content. Electrochemical tests show that the optimized B‐doped MnO ₂ requires an overpotential of only 411 mV to achieve a current density of 10 mA cm ⁻² in 1 M KOH electrolyte. Its OER performance surpasses that of most reported powder‐based MnO ₂ catalysts and demonstrates good stability.

The long-term durability of magnesium phosphate cement (MPC), particularly in repair applications, is critically limited by the chemical stability of its primary hydration product, struvite (MgNH ₄ PO ₄ ·6H ₂ O), in alkaline environments.

In architectural decoration, inorganic artificial stone has become a widely used material. However, it suffers from limited surface performance and functional simplicity. In this study, tourmaline was modified to enhance its negative-ion release capacity. The modified negative ion powder was used as a filler to prepare a negative ion-type UV curable coating (UVCC), which was then applied to the surface of artificial stone to obtain a negative ion-functional inorganic artificial stone. The results show that when 30 % by mass of CeO ₂ is added to 1200-mesh tourmaline powder, the negative ion release capacity of the composite powder increases from 197 ions/cm ³ to 586 ions/cm ³ . After heat treatment at 900 ℃ for 1 hour, the negative ion release capacity of the composite powder further rises to 828 ions/cm ³ . When 15 % of the modified negative ion powder is incorporated into the basic UVCC formula, the prepared negative ion-type UVCC coating enables the artificial stone to achieve a negative ion release capacity of over 500 ions/cm ³ , with a coating gloss higher than 90°, a hardness of 4 H, and an adhesion of grade 1. This work successfully improves both surface properties and health functionality, broadening the application potential of inorganic artificial stone.

Moisture‐electricity generation is a widely studied green power generation technology in recent years. Aiming at the defects of low output power and unsustainable output signal of moisture‐electricity generator (MEG), a new type of MEG is prepared using polypyrrole‐modified cleanroom wiper (PPy‐CRW) as electrodes. The electrodes exhibit good conductivity and can be infiltrated by sodium alginate (SA)‐based functional material, which reduces the contact resistance between electrode and functional material. In addition, graphene oxide (GO) is introduced to enhance the ion conductivity while increasing the amount of active functional groups. Additionally, the addition of hygroscopic salt LiCl and crosslinking with Ca ²⁺ makes MEG adsorb moisture continuously and maintain structural stability. The maximum output voltage of the PPy‐CRW‐MEG can reach 700 mV, with a stable output duration of up to 27 h in ambient, and the output power density reaches 37 μw cm ⁻² . This work expands the selection range of electrode materials for MEGs and provides a new view for MEG design.