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Araneose Ti3+ self-doped TiO2/SiO2 nanowires (RTiO2/SiO2) were prepared and anchored onto a polyethersulfone (PES) membrane. Careful characterizations and measurements indicated a covalent grafting of SiO2 onto reduced TiO2 (RTiO2) through Ti–O–Si linkages, acquiring uniformed RTiO2/SiO2 nanowires of almost complete anatase and benign hydrophilicity. The RTiO2/SiO2-based PES membrane showed a significantly enhanced visible light–driven degradation rate of methylene blue (MB) (90.7%), compared with that on bare PES (11.1%) and PES-RTiO2 (59.6%) membranes. The residual MB in filtered water was less than 5% after reusing three times. The normalized permeate flux of the modified membrane was 0.83, and the transmembrane pressure only increased by 0.4 MPa under irradiation of visible light. The improved performance of the PES-RTiO2/SiO2 was attributed to efficient intercept of MB molecular, light harvesting of visible light, and separation of charge carriers on araneose RTiO2/SiO2 nanowires. [ABSTRACT FROM AUTHOR]

The severe pollution and scarcity of clean water occurred worldwide. The photocatalysis on semiconductors is highly expected in decontamination or purification of water, although the performance of current semiconductors is extremely restricted by the low efficiency in utilization of sustainable solar energy. An effective strategy for this restriction is the construction of their surface heterojunctions. Unfortunately, the constructed heterojunctions have to be heterotypic because of the band discontinuities at the isotypic interface. Moreover, in most of cases, the constructing does not necessarily improve their performance efficiently due to the inertness of the ground state oxygen in trapping of the separated electrons. In this work, well-faceted TiO 2 with coexposed (001) and (101) and selective deposition of α-Fe 2 O 3 and Fe/Co-N 4 on the (001) facets was acquired. The overall photocatalytic activity of the well-designed composite in degradation of sulfathiazole has enhanced significantly by as much as 5.91 times compared to the bare faceted TiO 2 , and remained almost the same in 40 recycle usages. The significant performance of the designedly constructed composite was attributed to the remarkably enhanced light absorption, efficient separation of photo-induced charge carriers, oxygen activation and trapping of separated electrons through the Fe/Co-N 4 structure and the n-p-n dual heterojunction. Graphical abstract A designedly constructed photocatalyst with α-Fe 2 O 3 and Fe/Co-N 4 selectively deposited on (001) facets of TiO 2 was obtained, synergy in light harvesting, charge separation and oxygen activation was acquired for utilization of sustainable solar energy and oxygen in air, significant performance in STZ degradation was achieved. Image 1 Highlights • Selective deposition of α-Fe 2 O 3 and Fe/Co-N 4 on (001) facets of TiO 2 was acquired. • Significant performance of constructed photocatalyst in sulfathiazole degradation was achieved. • A synergy in light harvesting, charge separation and oxygen activation in photocatalysis was proposed. • Activation of oxygen in efficient trapping of separated electrons for producing of superoxide radicals is necessary. [ABSTRACT FROM AUTHOR]

In this work, Ag/AgCl/FeOCl (Ag–Fe) catalysts were successfully prepared via multistep routes in which Ag was uniformly anchored to the enriched Cl sites provided by exfoliated FeOCl nanosheets. Among these Ag–Fe catalysts, 5% Ag–Fe exhibited the highest pseudo first-order kinetic constant 0.1056 min−1 for photo-Fenton degradation of Rhodamine B (RhB), which was 11 times higher than that of FeOCl (0.0096 min−1). Ag–Fe catalysts exposed more coordinatively unsaturated Fe active sites to coordinate with H 2 O 2 due to the cleavage of Fe–Cl bond. The exposed coordinatively unsaturated Fe(III) active sites could capture the photoinduced electrons and reduce them to Fe(II), which boosted the separation efficiency of photogenerated charge carriers. Meanwhile, the photogenerated electrons of Ag0 transferred to the FeOCl, promoting the reduction of Fe(III) to Fe(II). In addition, the intensified visible light adsorption (SPR effect) was achieved after introducing Ag/AgCl nanoparticles on exfoliated FeOCl. Hydroxyl radicals (·OH) and holes (h+) were determined as the main reactive oxidative species (ROS) in the photo-Fenton degradation process. [Display omitted] • Highly dispersed of Ag/AgCl on exfoliated FeOCl nanosheets (Ag–Fe) was synthesized by a multistep method. • Enhanced photo-Fenton catalytic activity for RhB degradation was achieved under visible light. • Ag–Fe possessed rich coordinatively unsaturated Fe active sites to coordinate with more H 2 O 2. • The photogenerated electrons from Ag/AgCl accelerated the cycle of Fe(II)/Fe(III). [ABSTRACT FROM AUTHOR]

Photocatalytic process of Bi 0.8 Mn 0.2 OBr for CV degradation. [Display omitted] • The Mn-doping BiOBr generated intermediate state in band gap. • Oxygen vacancies and Mn-doping synergistic ameliorating separation of the photo-generated charge. • The intermediate energy states and oxygen vacancies play important role in charge separation. • DFT calculation confirmed the oxygen vacancies beneficial to molecular oxygen activation. • The in-depth mechanisms insight of charge separation and molecular oxygen activation. High-efficiency separation of photogenerated charges and molecular oxygen activation is very important for photocatalytic removal of organic pollutants. However, the current understanding of the effect mechanism of metal substitution for the separation of photo-generated charges and molecular oxygen activation is still poor. Herein, efficient manganese (Mn)-doped BiOBr hollow microspheres synthesis, systematic characterizations, and theoretical calculation discovered that Mn-doping could not only induce produce oxygen vacancies (OVs), but also can act as active sites for catalytic reactions. The induced production of OVs and Mn2+/Mn3+ by Mn optimal doping introduced into BiOBr can synergistic promote the separation of photogenerated charges and molecular oxygen activation leads to significantly enhances degradation of crystal violet (CV). Upon analysis, Mn-doping introducing unsaturated d-orbital with bridging O2– formation π-donation accelerated the separation of photo-generated charges. Meanwhile, the larger overlap of Mn-3d orbitals with O 2 -2p orbitals forms a π-donation bond with charge transfer from metal to O 2 leading to the oxygen–oxygen (O O) bond length and molecular oxygen activation. Finally, we proposed a possible mechanism to explain the highly efficient photocatalytic degradation performance of the acquired photocatalysts. This study provides not only a novel strategy for the rational design of highly active photocatalysts, but also in-depth insights into the separation of photo-generated charges and molecular oxygen activation. [ABSTRACT FROM AUTHOR]

• A novel membrane was constructed for the first time. • Efficient and simultaneous water evaporation and decontamination were achieved. • Synergic actions towards the high performances were identified. • Insights into the in-situ photodriven obtaining of clean water were approached. Construction of semiconductor-based membranes accommodates new routes for photothermal conversion and in-situ decomposing of pollutants in solar light-driven evaporation. In this work, a novel photocatalyst composed of MoO 3- x , BiOCl, and carbon nanotubes was surficial deposited on cellulose acetate membrane. High capillary pressure (∼600 kPa) guaranteed an effective capillary rise of water from hydrophilic membrane matrix. The water was extruded into ultra-fine droplets with a saturation vapor pressure as high as ∼1.75 × 105 Pa and a heat flux as much as ∼2.11 × 10−3 W mm−2. Moreover, the top-surficial film can harvest sufficient solar photons to generate charge carries, and the surface temperature of membrane can quickly increase to higher than 50 °C by thermalization through carriers relaxation, transference, and recombination on specific sites. Simultaneously, pollutants in water are efficiently decomposed by effectively separated charge carriers on designed spots. Synergistically, a steam generation rate of ∼7.75 kg m−2 h−1 was acquired and an almost complete removal of RhB and toluene was achieved. [ABSTRACT FROM AUTHOR]

• A novel Bi/BiOBr-Bi5+ was fabricated via a facile two-step approach. • Metallic Bi promoted carrier separation and intensified visible-light absorption. • Bi5+ self-doping decreased the bandgap and increased the carrier density. • The synergism between metallic Bi and Bi5+ was demonstrated. • Superoxide and photogenerated holes were the dominant active species. A novel composite photocatalyst of Bi/BiOBr-Bi5+ was successfully developed via a facile two-step procedure. The co-existence of self-doped Bi5+ and in-situ deposited Bi(M) was evidenced by X-ray diffraction, field-emission transmission electron microscope and X-ray photoelectron spectra. Its photocatalytic performance on the Rhodamine B (RhB) degradation under visible light irradiation displayed a significant improvement compared with that of Bi/BiOBr or BiOBr-Bi5+, which was mainly attributed to the synergistic effect between Bi(M) and Bi5+. For Bi(M), enhancement of visible-light absorption capacity was beneficial from surface plasmon resonance (SPR) effect while the promoted separation of photoinduced charge carriers was attributed to the formation of oxygen vacancies (OVs) and Schottky-barrier. Besides, Bi(M) induced a predominant exposure of (0 1 0) facet, further enhancing photocatalytic performance. Differently, Bi5+ brought a narrowed bandgap of BiOBr in increasing the carrier density. A plausible mechanism towards RhB degradation was proposed based on analysis of electron transfer pathway and determination of dominant active species. The work offers new routes to enhance the photocatalytic performance of Bi-based materials without introducing any impurities. [ABSTRACT FROM AUTHOR]

[Display omitted] • Construction of diverse dimensional heterojunctions succeed via simple assembly method. • Heterojunctions exhibited superiorities over individuals in TC-HCl removal with the 2D/2D to be the best. • An S-scheme was proposed and enhanced performances of heterojunctions were explained. • Vital importance of interfacial intimacy in heterojunctions was revealed. As a structural parameter, dimensionality is a key factor but was usually ignored in the design of novel heterojunction architectures in achieving their photocatalytic performances. Hence in this work, we obtained one-dimensional titanate nanotubes (TNTs), two-dimensional titanate nanoflakes (TNF) and three-dimensional titanate nanospheres (TNS) with facile treatments of TiO 2 by NaOH, and combined them with two-dimensional sulfur-doped g-C 3 N 4 nanoflakes (SCN), respectively, through magnetic and ultrasonic mixing in isopropanol. Their performances in photodegradation of tetracycline hydrochloride (TC-HCl) under simulated solar light irradiation exhibit significant superiorities of the composites over their individuals, while the photodegradation rates obtained on composites indicate a vital importance of their interfacial intimacy in heterojunctions. The photoactivity of TNF/SCN with a suitable face-face contact represents a rate constant as high as 0.1642 min−1, which is 1.58 and 2.65 times of what on TNS/SCN (0.1036 min−1) and TNTs/SCN (0.0619 min−1), respectively. Careful characterization and theoretical calculation indicated dense junction between different titanates and SCN via van der Waals integration. In these dense heterojunctions, an internal electronic field of about 0.75 V can automatically be formed between titanates and SCN during the assimilation of their Femi level by electronic coupling, to realize migration and separation of photogenerated carriers through an S-scheme. Moreover, the interfacial intimacy benefited from suitable dimensionality of titanates can promote the efficiency of S-scheme to acquire a prolonged lifetime of •OH and •O 2 –, and intraparticle transfer of TC-HCl towards their degradation. This work provides new insights into the rational design of heterostructures based on dimensional modulation on the interfacial affinity for accelerating the transfer of interfacial charge and the intraparticle transfer of contaminants. [ABSTRACT FROM AUTHOR]