Adopting the concurrent reduction of Cu₂O during hydrothermal preparation of ZnV₂O₄, metal–semiconductor heterojunction Cu/ZnV₂O₄ nanorods were synthesized and applied to the catalytic generation of methanol and ethanol from CO₂ aerated water under UV–vis light irradiation. 10Cu/ZnV₂O₄ obtained from 10 wt % composite amount of Cu₂O exhibited a total carbon yield of 6.49 μmol·g^–1·h^–1. The yield of CH₃OH and C₂H₅OH reached 3.30 and 0.86 μmol·g^–1·h^–1, respectively. 2.5Cu/ZnV₂O₄ displayed the highest ethanol yield of 1.58 μmol·g^–1·h^–1 due to the strong absorption in the visible light. Cu/ZnV₂O₄ was characterized using X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible (UV–vis) spectra, photoluminescence (PL) spectra, transient photocurrent response, and electrochemical impedance spectroscopy (EIS). Results showed that composite Cu⁰-ZnV₂O₄ increased the surface area and tuned the energy band position, which matches the reaction potential toward methanol and ethanol. The photocatalytic activity toward CH₃OH and C₂H₅OH on Cu/ZnV₂O₄ is attributed to faster transmission and a slow recombination rate of photogenerated carriers at the heterojunction interface. Multielectron reactions for the production of CH₃OH and C₂H₅OH are promoted. Free radical capture experiments indicated that the active species boost the reaction in the order of ^•OH > e^– > h⁺.

G-C3N4-based materials show potential for photoreduction ofCO2to oxygenates but are subjected to fast recombination of photogeneratedcharge carriers. Here, a novel Cu-dispersive protonated g-C3N4(PCN) metal-semiconductor (m-s) heterojunction from thermal reduction of a Cu2O/PCNprecursor was prepared and characterized using in situ X-ray diffraction,scanning transmission electron microscopy, X-ray photoelectron spectroscopy,ultraviolet-visible (UV-vis) spectra, photoluminescence (PL) spectra,transient photocurrent response, and electrochemical impedance spectroscopy(EIS). The Cu amount in Cu/PCN and the reduction temperature affected thegeneration of CH3OH and C2H5OH from the photoreaction of CO2-aeratedH2O. During calcination of Cu2O/PCN in N2at 550 degrees C, Cu2O was completelyreduced to Cu with even dispersion, and a m-s heterojunction was obtained.With thermal exfoliation, Cu/PCN showed a specific surface area and layerspacing larger than those of PCN. Cu/PCN-0.5 (12.8 wt % Cu) exhibited a total carbon yield of 25.0 mu molmiddotg-1under UV-visirradiation for 4 h, higher than that of Cu2O/PCN (13.6 mu molmiddotg-1) and PCN (6.0 mu molmiddotg-1). The selectivity for CH3OH andC2H5OH was 51.42 and 46.14%, respectively. The PL spectra, transient photocurrent response, and EIS characterizations indicatedthat Cu/PCN heterojunction promotes the separation of electrons and holes and suppresses their recombination. The calculatedconduction band position was more negative, which is conducive to the multielectron reactions for CH3OH and C2H5OHgeneration.

The occurrence of haze pollution significantly deteriorates air quality and threatens human health, yet persistent knowledge gaps in real-time source apportionment of fine particulate matter (PM_2.5) hinder sustained improvements in atmospheric pollution conditions. Thus, this study employed single-particle aerosol mass spectrometry (SPAMS) to investigate PM_2.5 sources and dynamics during winter haze episodes in Yinchuan, Northwest China. Results showed that the average PM_2.5 concentration was 57 μg·m⁻³, peaking at 218 μg·m⁻³. PM_2.5 was dominated by organic carbon (OC, 17.3%), mixed carbonaceous particles (ECOC, 17.0%), and elemental carbon (EC, 14.3%). The primary sources were coal combustion (26.4%), fugitive dust (25.8%), and vehicle emissions (19.1%). Residential coal burning dominated coal emissions (80.9%), highlighting inefficient decentralized heating. Source contributions showed distinct diurnal patterns: coal combustion peaked nocturnally (29.3% at 09:00) due to heating and inversions, fugitive dust rose at night (28.6% at 19:00) from construction and low winds, and vehicle emissions aligned with traffic (17.5% at 07:00). Haze episodes were driven by synergistic increases in local coal (+4.0%), dust (+2.7%), and vehicle (+2.1%) emissions, compounded by regional transport (10.1–36.7%) of aged particles from northwestern zones. Fugitive dust correlated with sulfur dioxide (SO₂) and ozone (O₃) (p < 0.01), suggesting roles as carriers and reactive interfaces. Findings confirm local emission dominance with spatiotemporal heterogeneity and regional transport influence. SPAMS effectively resolved short-term pollution dynamics, providing critical insights for targeted air quality management in arid regions.