Liqiu Zhang’s research while affiliated with Beijing Forestry University and other places

The Chaobai River Basin, which is a crucial ecological barrier and primary water source area within the Beijing–Tianjin–Hebei region, possesses substantial ecological significance. The gross ecosystem product (GEP) in the Chaobai River Basin is a reflection of ecosystem conditions and quantifies nature’s contributions to humanity, which provides a basis for basin ecosystem service management and decision-making. This study investigated the spatiotemporal evolution of GEP in the upper Chaobai River Basin and explored the driving factors influencing GEP spatial differentiation. Ecosystem patterns from 2005 to 2020 were analyzed, and GEP was calculated for 2005, 2010, 2015, and 2020. The driving factors influencing GEP spatial differentiation were identified using the optimal parameter-based geographical detector (OPGD) model. The key findings are as follows: (1) From 2005 to 2020, the main ecosystem types were forest, grassland, and agriculture. Urban areas experienced significant changes, and conversions mainly occurred among urban, water, grassland and agricultural ecosystems. (2) Temporally, the GEP in the basin increased from 2005 to 2020, with regulation services dominating. At the county (district) scale, GEP exhibited a north-west-high and south-east-low pattern, showing spatial differences between per-unit-area GEP and county (district) GEP, while the spatial variations in per capita GEP and county (district) GEP were similar. (3) Differences in the spatial distribution of GEP were influenced by regional natural geographical and socioeconomic factors. Among these factors, gross domestic product, population density, and land-use degree density contributed significantly. Interactions among different driving forces noticeably impacted GEP spatial differentiation. These findings underscore the necessity of incorporating factors such as population density and the intensity of land-use development into ecosystem management decision-making processes in the upper reaches of the Chaobai River Basin. Future policies should be devised to regulate human activities, thereby ensuring the stability and enhancement of GEP.

The transformation of photogenerated charge carriers (PC) in variable dimensional photocatalyst plays a pivotal role in unraveling the generation of reactive species (RS). However, the dimensional structure–activity relationship in photocatalysis remains elusive, with limited insights into its intricacies. Herein, we report a controlled synthesis strategy by using polyvinyl pyrrolidone (PVP)-assisted precipitation method for BiOI photocatalyst. Due to the steric hindrance of PVP, the 3D microsphere (3D-PVP0.5) and porous structure (3D-PVP1) of BiOI catalysts have been successfully prepared at room temperature. The 3D-PVP1 photocatalyst contains abundant mesopores and larger pores, which significantly shorten the diffusion distance of PC. Also, these PC in porous structure is beneficial for transferring from the inner phase to the surface of materials. Combined with optical property and radicals trapping experiments, the recombination rate of PC in porous structure performs a significant decrease, leading to the generation of more dominated ROS (•O2⁻ and h⁺). The •O2⁻ played a dominated role (86.98% of contribution rate) in photodegradation of tetracycline (TC) in 3D-PVP1 photocatalytic process. Compared with 2D nanosheet of BiOI (16.7% removal rate of TC), the as-prepared 3D porous structure of BiOI catalyst exhibits unique stable and high removal capacities (90.5%) for TC photodegradation under visible light irradiation. The kobs of 3D-PVP1 photocatalyst increased by 5.1 times than that of 2D nanosheet. To investigate its practical application, the effects of inorganic anions and pH have been systematically studied. This work sheds light on the design of variable dimension BiOI catalyst and provides more insight into the transfer mechanism of PC.