Jiaqiang Wang

Addressing global phosphorus scarcity and eutrophication, MgO-based adsorbents face challenges of slow kinetics and low active-site utilization. In this study, a waste biomass-derived carbon aerogel (CA) was used as a support for a one-step pyrolysis method, simultaneously constructing a porous structure and achieving high-dispersion MgO loading. Results showed a maximum adsorption capacity of 399.8 mg P/g. Kinetic studies indicated 165.4 mg P/g adsorbed within 5 min, with 90% saturation achieved within 40 min. The Pseudo-second-order kinetic constants increased 11-fold compared to commercial MgO. By integrating experiments, machine learning (ML), and density functional theory (DFT), a multiscale investigation revealed the synergistic effect between MgO and the carbon aerogel support. It was demonstrated that the rapid adsorption kinetics originated from the macroporous structure of the support rather than a high specific surface area. Furthermore, urea participation during pyrolysis modulated the pyridinic-N content of the CA, thereby modifying the pH adaptability of the material. Collectively, this study provides a foundation for reusing waste biochar and designing high-performance phosphate adsorbents.

A core–shell structured polydopamine@covalent organic framework (PDA@COF) was rapidly constructed via a facile sonochemical strategy. The resulting organic heterostructure exhibited excellent photocatalytic activity for H₂O₂ production.

Solar steam generation (SSG) has garnered significant attention for its potential in water purification applications. While composites with physically combined structures based on semiconductors or biomass have been developed for SSG, there remains a critical need for low-cost, high-efficiency devices. In this study, TiO₂ composites exhibiting excellent stability, high solar absorption, porous microstructure, and hydrophilic surfaces were identified as effective materials for SSG and water purification for the first time. A novel SSG device was designed by decorating TiO₂ onto three-dimensional carbonized Osmanthus fragrans leaves (TiO₂/carbonized OFL). Compared to directly carbonized OFL (without TiO₂) and Osmanthus fragrans leaves with templated TiO₂ (OFL-templated TiO₂), the TiO₂/carbonized OFL carbon composites demonstrated enhanced solar absorption, achieving over 99% in the visible region and more than 80% in the near-infrared region. Under solar illumination of 1 kW·m⁻², the TiO₂/carbonized OFL device achieved a high water evaporation rate of 2.31 kg·m⁻²·h⁻¹, which is 1.6 times higher than that of carbonized OFL and 3.45 times higher than OFL-templated TiO₂. Additionally, the TiO₂/carbonized OFL system exhibited remarkable efficiency in treating pharmaceutical wastewater, with a chemical oxygen demand (COD) removal efficiency of 98.9% and an ammonia nitrogen removal efficiency of 90.8% under solar radiation.

Synthesis of the photocatalysts with near-infrared light response usually involves upconversion materials or plasmon-assisted noble metals. Herein, NiTiO₃/TiO₂ was synthesized by using waste tobacco stem-silks as biotemplates and tetra-tert-butyl orthotitanate and nickel nitrate as precursors in a one-pot procedure. NiTiO₃(1.0)/TiO₂(TSS) with a mass percent of Ni 1.0% exhibited very high visible-light photocatalytic efficiency in photodegradation of tetracycline hydrochloride (TC), which is 8.0 and 2.3 times higher than TiO₂ prepared without templates and TiO₂(TSS) prepared without Ni, respectively. Interestingly, NiTiO₃(1.5)/TiO₂(TSS) even exhibited good activity under NIR light (λ = 840~850 nm) without upconversion materials or plasmon-assisted noble metals, which is 2.8 and 2.2 times than TiO₂ prepared without templates and TiO₂(TSS), respectively. The boosting photocatalytic activity has been shown to be attributed to efficient charge separation and transfer across a direct Z-scheme heterojunction between NiTiO₃ and TiO₂ and enhanced light-harvesting ability of special flaky structure reduplicated from tobacco stem-silks. This reported strategy provides a new idea for the multifunctional utilization of waste tobacco stem-silks and the synthesis of novel photocatalysts for the potential application in wastewater treatment.