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The improvement of photocatalytic performance is limited by the reduction of carrier redox capacity. Effective design of micromorphology and heterostructure is expected to overcome this obstacle. 3D cross-linked Bi 2 O 2 SiO 3 -BiOM-Si 2 Bi 24 O 40 (BSO-BOM, M∈Cl, Br, I) with lamellar porous and double heterostructure are prepared in situ by an environmentally friendly hydrothermal deposition method. The process parameters are continuously optimized by exploring the modification effect of the pore-forming agent SiO 2 and different halides in the composite preparation. The introduction of SiO 2 changes the morphology of BSO, and a more effective heterogeneous interface interaction can be obtained in BSO-BOM. The construction of 3D cross-linked BSO-BOM with lamellar porous structure makes BSO-BOB better for nanocrystallization, which reduces material agglomeration, shortens the physical distance of carrier migration to the surface, and has a more suitable band gap position. Thereby accelerating the migration and diffusion of h+ so that it directly reacts with rhodamine B (Rh B) to form CO 2 and H 2 O. After adjustment, these photocatalysts can reach 81.98% (BSO-BOI, 150 min), 98% (BSO-BOC, 90 min) and 100% (BSO-BOB, 60 min) of Rh B degradation, respectively. This work provides a feasible strategy for morphology control and free radical modification of heterogeneous photocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Curved microflower photocatalysts Bi 12 SiO 20 -Bi 2 O 2 SiO 3 -BiOCl with large surface area was synthesized. • The photocatalyst is designed from a combination of hydrochloric acid and dopamine hydrochloride. • The difficulty of the photocarrier separation is reduced by modulation of morphology and heterogeneous interfaces. • DBSO-10 can efficiently degrade different dyes and antibiotics in a short time. Heterostructures with intimate contact interfaces and well-matched band structure construction are considered to be one the effective methods to promote photogenerated carrier separation and photocatalytic semiconductor activity. Herein, a simple joint post-modification method of hydrochloric acid and dopamine hydrochloride mediated under acidic conditions was proposed. Bi 12 SiO 20 -Bi 2 O 2 SiO 3 -BiOCl curved microflower photocatalyst with double heterojunction and large specific surface area was prepared. Hydrochloric acid and dopamine hydrochloride act as reactants and halogen sources in the composite photocatalyst, and their amount precisely control the surface morphology and the thickness of nanosheets. Benefiting from the synergistic effect of morphology regulation and interface optimization, the DBSO-10 not only changes its morphology from the original bone rod structure to the curved microflower structure with a large specific surface area, but also formes a double type-II heterostructure with tight interface connection. And the new microflower photocatalyst can achieve a degradation rate of 99.7 % in 20 min, which is 40 times higher than that of Bi 12 SiO 20 -Bi 2 O 2 SiO 3 photocatalyst. Notably, the material can also effectively degrade five catalysts including dyes and antibiotics within 1 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • A ion exchange technology was used to construct double heterojunction catalysts containing solid solution. • The adsorption mechanism and catalytic performance of the catalysts are investigated. • The catalysts achieve rapid degradation of Rh B, MO and TCH under visible light condition. The search for a photocatalyst toward degradation of different organic dyes and antibiotic remains a challenging task due to the difficult of controllable micro-morphology and double heterojunction in the same photocatalytic system. Herein, a ion exchange technology was used to obtain double heterojunction Bi 12 SiO 20 /Bi 2 O 2 SiO 3 /BiOX (BOSX, X ∈ Cl, Br, I). Moreover, three series of two-dimensional materials Bi 12 SiO 20 /Bi 2 O 2 SiO 3 /BiOX m Y n (BSOXYK, X, Y ∈ Cl, Br, I, m + n = 1, K = m/n) containing solid solution were realized, which have excellent adsorption catalytic synergistic effect on rhodamine B, methyl orange and tetracycline hydrochloride. This synergistic effect of adsorption and catalysis is due to the change of material morphology, double heterojunction interaction and continuous band regulation. After regulation, this series of photocatalysts show good degradation effects on a variety of pollutants, namely, the degradation rate on 30 mg·L-1 Rh B, 50 mg·L-1 TCH and 10 mg·L-1 MO can up to 99 % (BSOCI4), 85% (BSOCI4) and 99% (BSOCI1) respectively, which makes this series of materials have a wide range of applications. Therefore, this work provides a new insight in exploring double heterojunction catalysts with solid solution to realize the degradation of different organic pollutions in the same system under visible light. [ABSTRACT FROM AUTHOR]

Bismuth silicate (Bi 2 SiO 5 and Bi 12 SiO 20 , BSO) films were aimed to grow uniformly on SiO 2 photonic crystal (SPC) via spin-coating. The as-prepared BSO-SPC exhibited better photocatalytic decomposition of Rhodamine B (RhB) than that of the ordinary BSO film under ultraviolet (UV) irradiation. The improvement of photocatalytic activity of BSO can be attributed to the enhancement of light harvesting efficiency by SPC. The results show that the photon localization of SPC plays an important role in enhancing the light absorption of BSO. The influences of the particle diameter of SiO 2 , the thickness of both SPC and BSO layer on the photon localization of SPC were investigated. This work provides a simple method to improve the light harvesting efficiency of photocatalyst and extends the application of photonic crystal. In addition, the recovery and reuse of immobilized BSO-SPC photocatalyst make it more suitable for practical application. • Photonic crystals can improve the light absorption efficiency of photocatalysts. • Photonic band gap plays an important role in improving photocatalytic performance. • The immobilized photocatalyst can be recycled without secondary pollution. [ABSTRACT FROM AUTHOR]

Aurivillius oxide layered materials are formed by bismuth oxide and pseu-do-perovskite layers, which usually presents a mica-like lamellar structure, that is easy to stack with each other, affecting the exposure of active sites, thereby reducing its photocatalytic performance. Herein, the organic modifier is used to adjust the morphology to obtain Bi 24 Si 2 O 40 -Bi 2 O 2 SiO 3 (BSO) with three-dimensional flower-like structure. Furthermore, the optimization of morphology promotes the effective formation of heterostructures, organic-mediated morphology growth and the regulation of heterojunction effectively improves the activity of superoxide radicals (•O 2 −) and holes (h+). Therefore, the organic-modified MBSO-2 shows excellent photocatalytic performance, and its degradation rates of rhodamine B (RhB), ciprofloxacin (CIP) and norfloxacin (NOR) can reach 98.7%, 87.4% and 89.0%, respectively. Moreover, the great improvement of the degradation of RhB and NOR by MBSO-2 can be attributed to the important role played by its active species (h+ and •O 2 −), which shows that it is more conducive to improving the degradation of pollutants with h+ and •O 2 − as the degradation path. The modification strategy of organic-mediated lamellar growth provides a new idea for the morphology control of layered metal oxide photocatalysts and broadens its application. • Flower-like BSO is controlled via complex with organic and assistance of hydroxyl. • The change of the active species adjusts the degradation path of the photocatalyst. • The as-prepared MBSO-2 can effectively degrade different pollutants. [ABSTRACT FROM AUTHOR]