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The degradation of organic pollutant by photocatalytic technology is an emerging and effective approach to purify water resources. Herein, we reported a heterostructure with selective adsorption and photocatalysis for the efficient removal of organic pollutant. The photocatalyst was comprised of up-converting nanoparticle (UCNP) coated with Ag/Bi 2 O 3. The specific crystallinity of Bi 2 O 3 facilitated the selective adsorption of organic molecules with negative polarity, Ag nanoparticles loaded on Bi 2 O 3 promoted the visible light absorption, and the up-conversion property of UCNP turned near-infrared light into ultraviolet and visible light improving further light-harvesting efficiency in the whole solar spectrum. The adsorption process for organic pollutants over Ag/UCNP@Bi 2 O 3 obeyed the pseudo-second-order and the Langmuir isotherm models, and the maximum Langmuir adsorption capacity for tetracycline reached to 717.4 mg/g at pH 7. Meanwhile, the photocatalytic degradation rate of Ag/UCNP@Bi 2 O 3 for tetracycline (100 mg/L) achieved to 0.0037 min−1 under Xenon lamp irradiation after the adsorption equilibrium. This study provided a feasible strategy to develop photocatalysts with efficient adsorption and photocatalytic ability for organic pollutant from water. The schematic illustration of the photocatalytic mechanism of the Ag/UCNP@Bi 2 O 3 NPs, and the energy transfer mechanisms show the up-conversion process of Yb3+ and Tm3+ doped UCNPs under 980 nm excitation. [Display omitted] • The specific crystallinity of Bi 2 O 3 facilitated selective adsorption. • The interface interaction of Ag/Bi 2 O 3 significantly improved photocatalytic effect. • Up-conversion nanoparticle coupled with Ag/Bi 2 O 3 fulfill whole solar spectrum. • Tetracycline could be selectively adsorbed and further photodegraded. [ABSTRACT FROM AUTHOR]

The removal of organic contaminants from water poses a significant challenge that can be tackled by integrating adsorption and photocatalytic degradation functions in a single architecture. However, traditional powdery nanomaterials face challenges in separation and lack synergistic function, hampering their practical application. This study presents a one-step hydrothermal synthesis of a convenient recyclable Bi 2 O 2.33 /Bi 2 O 3 @ECNF (electrospun carbon nanofibers), which combines both adsorption and photocatalytic performance. The Bi 2 O 2.33 /Bi 2 O 3 exhibits high adsorption removal of methyl orange (MO), reaching 94.56 % and a maximum capacity of 213.13 mg g−1. Additionally, the Bi 2 O 2.33 /Bi 2 O 3 shows a high charge transfer rate, strong redox ability, and efficient removal of Rhodamine B (RhB) at 83.01 %. Loading the Bi 2 O 2.33 /Bi 2 O 3 on lightweight carbon fibers allows for easy recycling. The Bi 2 O 2.33 /Bi 2 O 3 @ECNF demonstrates excellent stability and reusability, with a removal rate of 87.37 % for tetracycline hydrochloride (TCH) at high concentrations. This work presents a promising solution for the practical application of photocatalysts by overcoming the limitations of single photocatalysts and minimizing secondary pollution from single adsorbents. [Display omitted] [ABSTRACT FROM AUTHOR]

Removing noxious dyes and detecting excessive metal ions in water are both effective means to prevent damage from contaminants and ensure water safety. The emphasis problems were addressed by preparation a polyacrylamide chitosan (PAAM/CS) hydrogel. Polyacrylamide (PAAM) provides overall mechanical strength to carry loads and facilitate circulation, chitosan (CS) provides adsorption positions with high adsorption capacity. Which made that PAMM/CS hydrogel efficiently performed sorption of xylenol orange (XO). As the functional dye, XO binds to PAAM/CS and confers colorimetric properties on PAAM/CS hydrogels. XO sorbed hydrogel realized fluorescence dual-signal detection of Fe3+ and Al3+ in water. The significant swelling and adsorption potency of the hydrogel, combined with the dual-signal detection capability of XO sorbed hydrogel, make this hydrogel a versatile material for environmental applications. • Polyacrylamide chitosan hydrogel was prepared as adsorbent. • Adsorption mechanism is mainly based on electrostatic attraction. • After five adsorption cycles, the composite hydrogel still achieved 83.29 % removal of xylenol orange. • XO sorbed hydrogel realized fluorescence dual-signal detection of Fe3+ and Al3+ in water. [ABSTRACT FROM AUTHOR]