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To boost the adsorption‐photocatalytic performances of biochar in wastewater treatment, biochar was modified with ternary metal oxides ZnO, Sm2O3, and MgO (ZnSm/Mg‐biochar) via the one‐step pyrolysis method. The optimal 2b‐ZnSm/Mg‐biochar with a Zn/Sm molar ratio of 1:1 exhibited the better removal activity of RhB in comparison with biochar, 2‐Mg/biochar, and b‐ZnSm/biochar. The removal efficiency and adsorption capacity of 2b‐ZnSm/Mg‐biochar was 99.46% and 979.22 mg g−1 for RhB solution of 410 mg g−1, respectively. The adsorption kinetics and isotherms of ZnSm/Mg‐biochar composites were as described by second‐order and Langmuir models, respectively. The abundant vacant sites at the junction interface of ZnO, Sm2O3, MgO, and biochar were favorable for the adsorption and photon capturing, achieving the efficient photo‐conversion of RhB under the stimulated solar‐light irradiation. [ABSTRACT FROM AUTHOR]

[Display omitted] • S-doped biochar was modified by Ag 2 S and MgO for boosting adsorption-photocatalytic activity. • The adsorption activity of Ag 2 S-MgO/S-BC was better than its photocatalytic activity. • Langmuir well fitted with the adsorption isotherms of Ag 2 S-MgO/S-BC. • Second-order model well describes with the adsorption kinetics of Ag 2 S-MgO/S-BC. S-doped biochar was co-modified with Ag 2 S and MgO (Ag 2 S-MgO/S-BC) for enhancing adsorption-photocatalytic performance in RhB elimination. The prepared Ag 2 S-MgO/S-BC heterojunctions were better for adsorption-photocatalytic removal of RhB as compared to Ag 2 S and MgO alone for S-doped biochar modifying. Langmuir and second-order models well described the adsorption isotherms and kinetics of Ag 2 S-MgO/S-BC, respectively. The adsorption-photocatalytic elimination of RhB over optimal 4-Ag 2 S-MgO/S-BC was reached to 97.60 % under solar-light irradiation within 120 min, and the photo-corrosion resulted the declined removal efficiency of RhB to 91.87 % after five cycle times. Ag 2 S-MgO/S-BC was thus the super candidate for adsorption and photocatalytic application in wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • MoS 2 -MgO/S-BC were prepared for boosting the removal capacity of TCH. • The adsorption activity of MoS 2 -MgO/S-BC was higher than the photocatalytic activity. • Langmuir well fitted with the adsorption isotherm of MoS 2 -MgO/S-BC. • Second-order model well described with the adsorption kinetics of MoS 2 -MgO. MoS 2 and MgO co-modified biochar with S-doping (MoS 2 -MgO/S-BC) was prepared for facilitating the adsorption-photocatalysis towards tetracycline hydrochloride (TCH) elimination under solar-light irradiation. MoS 2 -MgO/S-BC had the better adsorption-photocatalytic activity in comparison to S-BC, b-MgO/S-BC, and 2-MoS 2 /S-BC, and its removal efficiency was intensively affected by MoS 2 and MgO loading contents. The experimental factors such as bulk dosage, TCH concentration, inorganic salts, and pH also influenced the adsorption-photocatalytic capacity of MoS 2 -MgO/S-BC. The highest adsorption capacity (239.52 mg g−1) and removal efficiency (93.70 %) were obtained by optimal 2b-MoS 2 -MgO/S-BC for 200 mg/L TCH solution within 120 min. The adsorption process of MoS 2 -MgO/S-BC was well described by Langmuir isotherm and second-order model. The boosted adsorption-photocatalytic performance of MoS 2 -MgO/S-BC in TCH removal was ascribed to the abundant vacant sites generated from the functional groups of S-doped biochar and lattice defects of MoS 2 and MgO, and the efficient separation and migration of photoinduced e-/h+ at the junction interface among MoS 2 , MgO, and S-BC. [ABSTRACT FROM AUTHOR]

• Ga 2 S 3 /S-modified biochar (Ga/S-BC) was prepared by high-temperature sulfurization. • Ga/S-BC exhibited the efficient adsorption capacity for ciprofloxacin removal. • Electrostatic interaction was vital for the physisorption process of Ga/S-BC. Ga 2 S 3 and sulfur co-modified biochar (Ga/S-BC) composites were prepared for enhancing the adsorption of ciprofloxacin from sugarcane bagasse via the high-temperature sulfurization. In contrast with sulfur-modified biochar, Ga/S-BC exhibited the better adsorption capacity for ciprofloxacin removal. The increasing Ga content induced to the climbing and then declining adsorption activity of Ga/S-BC. Among these obtained Ga/S-BC composites, optimal 3-Ga/S-BC with a Ga content of 7.40% and surface area of 681.67 m2 g−1 exhibited the superior capacity of 330.21 mg g−1. The adsorption capacity of 3-Ga/S-BC declined to 301.66 mg g−1 after nine cycles. pH and inorganic salts also affected the adsorption capacity of 3-Ga/S-BC for ciprofloxacin removal. The adsorption isotherms of obtained Ga/S-BC composites were well described by Langmuir isotherm, and their adsorption kinetics were well estimated via second-order model. The adsorption performance of 3-Ga/S-BC in ciprofloxacin removal was a physisorption and spontaneous process. [ABSTRACT FROM AUTHOR]

• Fe-La oxides loaded MgO nanosheets were prepared via the impregnation route. • Fe-La/MgO exhibits the excellent adsorption capacity of phosphate. • La 2 O 3 can enhance the adsorption activity of MgO for methyl orange removal. • The competitive adsorption exists in the binary system of methyl orange and phosphate. Fe-La oxides co-loaded MgO (Fe-La/MgO) nanosheets were prepared for the adsorption of methyl orange and phosphate in single and binary systems. The Fe-La oxides content, concentration ratio of methyl orange to phosphate, inorganic ions, and pH values greatly affect the competitive adsorption performance of Fe-La/MgO in binary system. Among these obtained Fe-La/MgO composites, Fe-La/MgO-2 with a total Fe-La oxides content of 4.0 wt% and a Fe/La molar ratio of 1:1 presents the best adsorption capacity of phosphate (38.82 mg g−1) within 120 min, and La 2 O 3 /MgO with a La 2 O 3 content of 2.0 wt% exhibits the highest adsorption activity of methyl orange (30.38 mg g−1) within 40 min in single system. However, the adsorption capacities of Fe-La/MgO-2 for phosphate and methyl orange in binary system are respectively 39.51 mg g-1 and 16.52 mg g−1 within 40 min due to the competitive adsorption between phosphate and methyl orange. The low pH is favorable for the separation of phosphate and methyl orange in binary system. Langmuir isotherm and second-order model can well fit with the adsorption isotherms and kinetics in single system. In addition, these adsorption processes of Fe-La/MgO-2 for methyl orange and phosphate in single system are the physisorption and chemisorption governed by the intra-particle diffusion and external mass transfer, respectively. [ABSTRACT FROM AUTHOR]

• Mg/N-C from sugarcane bagasse was prepared by a one-pot pyrolysis route. • Mg/N-C shown the excellent adsorption capacity for the MO removal. • Mg/N-C active carbon presented the superior adsorption stability. • Mg/N-C for the MO removal was a spontaneous and physisorption process. MgO/N-doped active carbon (Mg/N-C) derived from sugarcane bagasse was prepared for the removal of methyl orange (MO). Mg/N-C composites presented the better adsorption capacity than that of active carbon and N-doped active carbon, of which the maximum adsorption capacity of 2-Mg/N-C-b2 for the MO removal is 384.61 mg g−1. The effects of MgO dosage, N-doped content, pyrolysis temperature, pH value, inorganic ions and solution temperature on the adsorption performance of Mg/N-C composites in the MO removal were investigated in detail. The pseudo-second order model and Langmuir isotherm model fitted well with the adsorption kinetics and isotherms of Mg/N-C. The rate-determining step was the boundary diffusion and intra-particle diffusion. The adsorption process of 2-Mg/N-C-b2 was a spontaneous and physisorption process. [ABSTRACT FROM AUTHOR]

Developing highly recyclable photocatalysts is crucial for the industrial application of solar-light driven wastewater treatment. Hence, S,N,P-codoped carbon (SNP–C) nanofibers are modified with MoS 2 (MoS 2 /SNP-C) via the electrospinning and nonthermal plasma-sulfurized approaches for enhancing the adsorption and photocatalytic efficiency. The adsorption and photocatalytic capacities of MoS 2 /SNP-C composites for visible-light induced RhB removal are greatly affected by the mass ratio of Mo/P and sulfurized time. Langmuir and second-order models well fit with the adsorption isotherms and kinetics of these composites, respectively. 4-MoS 2 /SNP-C with the nominal Mo/P mass ratio of 12:1 and the sulfurized time of 30 min presents the best adsorption-photocatalytic activity, and its adsorption capacity and removal efficiency of RhB are 728.80 mg g−1 and 99.79%, respectively. The in-situ plasma induced sulfurization is likely to generate the sufficient vacant sites of RhB adsorption and the tight interface between MoS 2 and SNP-C for the rapid transfer of charge carriers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Polypyrrole efficiently enhanced the adsorption activity and durability of PPy/Mg-Al for RhB. • Langmuir fitted with the adsorption isotherms of PPy/Mg-Al composites. • Second-order model described with the adsorption kinetics of PPy/Mg-Al composites. • PPy/Mg-Al exhibited a spontaneous and endothermic adsorption process. Polypyrrole-decorated Mg-Al layered double oxides (PPy/Mg-Al) were prepared via the in-situ polymerization for enhancing the adsorption capacity of Rhodamine B (RhB). For comparison to Mg-Al layered double oxides, PPy/Mg-Al composites presented the better adsorption capacity, which climbed and then declined with an increase PPy content. The optimal 2-PPy/Mg-Al had the best Langmuir adsorption capacity of 200.10 mg g−1, and its tested adsorption capacity decreased from 137.13 to 118.13 mg g−1 after seven cycles due to the change in the valance sates of surface compositions and surface discharge nature. 2-PPy/Mg-Al exhibited a spontaneous and endothermic adsorption process for RhB removal, and its adsorption isotherms and kinetics were respectively described by Langmuir and second-order models. Hence, the in-situ polymerization of pyrrole was a promising route to enhance the adsorption activity of Mg-Al LDO for dyes removal from wastewater. [ABSTRACT FROM AUTHOR]

To boost the adsorption activity of Ficus virens biochar for dye removal, S-doped biochar was co-modified by MgO and B 2 O 3 (Mg-B/S-BC) via one-pot sulfurization. Mg-B/S-BC exhibits the higher adsorption capacity than S-doped biochar, MgO/biochar and B 2 O 3 /biochar for rhodamine B (RhB). The adsorption capacity of optimal Mg-B/S-BC is 1195.25 mg g−1, and declines to 1142.97 mg g−1 after nine cycles. The adsorption isotherms and kinetics of S-biochar based composites are well matched with Langmuir and second-order models, respectively. The mechanism of RhB adsorption on 4d-Mg-B/S-BC composites is through electrostatic attraction, H-bonding and ion exchange interactions, and it is a spontaneous process of physical adsorption and heat absorption. The field-scale results suggest that the adsorption capacity of optimal Mg-B/S-BC is 487.01 mg g−1, while reduces to 429.63 mg g−1 for RhB after nine cycles. The optimal Mg-B/S-BC exhibits the excellent adsorption activity for field-scale removal of tetracycline hydrochloride, ciprofloxacin, and methyl orange. Hence, Mg-B/S-BC composite is a promising material for industrial application in wastewater purification. • S-doped biochar was co-modified by MgO and B 2 O 3 via one-pot sulfurization. • Mg-B/S-BC presents excellent adsorption capacity for organic pollutants. • Electrostatic interaction, H-bonding and ion exchange is vital for the physisorption process of Mg-B/S-BC. • The maximum capacity of RhB adsorption on Mg-B/S-BC can reach 1195.25 mg g−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • B,N-codpoed biochar was modified by ZnFe 2 O 4 via the microwave-assisted pyrolysis. • ZnFe/BN-biochar exhibited excellent adsorption-photocatalytic capacity for TCH. • ZnFe/BN-biochar presented superior adsorption-photocatalytic durability for TCH. • Adsorption of TCH over ZnFe/BN-biochar was a spontaneous and physisorption process. B, N-codoped biochar was modified by ZnFe 2 O 4 (ZnFe/BN-biochar) via the one-pot microwave-assisted pyrolysis for enhancing the adsorption-photocatalytic elimination of tetracycline hydrochloride (TCH). The addition of ZnFe 2 O 4 could enhance the adsorption and photocatalytic capacity of B,N-codoped carbon under solar light irradiation. Among these composites, the optimal 3-ZnFe/3b-BN-biochar could remove 98.19 % of 150 mg L−1 TCH solution within 120 min, and its adsorption capacity estimated by Langmuir was 244.34 mg g−1 for TCH removal. However, the removal efficiency of TCH over 3-ZnFe/3b-BN-biochar decreased to 89.45 % after seven cycles. The photocatalytic and adsorption kinetics of biochar-based composites for TCH removal were well descried with Langmuir-Hinshelwood and second-order models, respectively. In addition, Langmuir well fitted with the adsorption isotherms of biochar-based composites. The adsorption process of TCH over 3-ZnFe/3b-BN-biochar was a spontaneous and physisorption process. Hence, 3-ZnFe/3b-BN-biochar was a promising material for the adsorption and photocatalytic elimination of pollutants in wastewater. [ABSTRACT FROM AUTHOR]

• The rare-earth oxides modified Mg-Al LDO nanosheets were prepared. • La 2 O 3 /Mg-Al composites enhance the adsorption-photocatalytic activity. • Junction structure favors the visible light harvesting and the charge tansfer. Mg-Al layered double oxides (LDO) nanosheets were modified by rare-earth oxides such as La 2 O 3 , Sm 2 O 3 , and Er 2 O 3 (M/Mg-Al, M = La, Sm, and Er) via a one-pot hydrothermal route for the solar-light induced adsorption-photocatalytic degradation of tetracycline hydrochloride (TCH). These rare-earth oxides can greatly enhance the adsorption-photocatalytic activity of Mg-Al based composites, especially La 2 O 3. It's attributed to the efficient adsorption of vacant sites and the rapid transfer and separation of charge carriers at the junction interface. The La 2 O 3 content, pH value, and inorganic ions intensively affect the adsorption-photocatalytic performance of La/Mg-Al. The optimal 2-La/Mg-Al with the La 2 O 3 content of 4.35 % exhibits the best removal efficiency of TCH and the excellent photocatalytic durability. The removal efficiency of TCH (100 mg L−1) is 99.87 % within 110 min, and reduces to 95.88 % after five cycle times. The adsorption isotherms and kinetic behaviors of M/Mg-Al (M = La, Sm, and Er) for TCH removal are well described by Langmuir isotherm and second-order model, respectively. The active radicals such as OH and O 2 − are responsible for the solar light driven photocatalytic degradation of TCH. [ABSTRACT FROM AUTHOR]

Adsorption-photo-reduction is considered as a potential route to remove Cr(VI) from wastewater. To explore the novel photocatalysts with efficient adsorption-photocatalytic activity, flower-like hierarchical ZnS-Ga 2 S 3 heterojunction was prepared for the solar-light-driven reduction of Cr(VI). Its adsorption-photocatalytic capacity is greatly affected by the ZnS/Ga 2 S 3 molar ratio, Cr(VI) content, pH values, and inorganic ions. Among these obtained composites, ZnS-Ga 2 S 3 -3 with a ZnS/Ga 2 S 3 molar ratio of 3:1 exhibits the best adsorption-photocatalytic capacity. The adsorption capacity of ZnS-Ga 2 S 3 -3 is 54.42 mg g−1, and its total removal efficiency is 99.10% for 100 mg L−1 Cr(VI) solution after 160 min. In addition, the adsorption-photo-reduction performance of ZnS-Ga 2 S 3 -3 is slightly deactivated after nine cycle times. The Langmuir, pseudo-second-order, and first-order models well describe the adsorption isotherm, adsorption kinetic, and photo-reduction kinetic of ZnS-Ga 2 S 3 -3, respectively. The synergy effect of ZnS and Ga 2 S 3 are favorable for the efficient transfer and separation of charge carriers, and provide sufficient vacant sites at the junction interface for the adsorption of Cr(VI). Image 1 • Flower-like hierarchical ZnS-Ga 2 S 3 was prepared by the hydrothermal route. • ZnS-Ga 2 S 3 heterojunction has excellent adsorption-photocatalysis capacity. • ZnS-Ga 2 S 3 exhibits slight deactivation for Cr(VI) removal after nine cycle times. [ABSTRACT FROM AUTHOR]