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The construction and regulation of built-in electric field (BIEF) are considered effective strategies for enhancing the oxygen evolution reaction (OER) performance of transition metal-based electrocatalysts. Herein, we present a strategy to regulate the electronic structure of nickel-iron layered double hydroxide (NiFe-LDH) by constructing and enhancing the BIEF induced by in-situ heterojunction transformation. This concept is demonstrated through the design and synthesis of Ag 2 S@S/NiFe-LDH (p-n heterojunction) and Ag@S/NiFe-LDH (Mott-Schottky heterojunction). Benefiting from the larger BIEF of Mott-Schottky heterojunction, efficient electron transfer occurs at the interface between silver (Ag) and NiFe-LDH. As a result, Ag@S/NiFe-LDH exhibits excellent OER performance, requiring only a 232 mV overpotential at 1 M KOH to achieve a current density of 100 mA cm -2 , with a small Tafel slope of 73 mV dec -1 , as well as excellent electrocatalytic durability. Density functional theory (DFT) calculations further verified that stronger BIEF in Mott-Schottky heterojunction enhances the electron interaction at the interfaces, reduces the energy barrier for the rate-determining step (RDS), and accelerates the OER kinetics. This work provides an effective strategy for designing catalyst with larger BIEF to enhance electrocatalytic activity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The persistent release of tetracycline into the environment significantly endangers both ecosystems and human health. Zinc indium sulfide (ZnIn 2 S 4 ) capable to degrade tetracycline pollutants under visible light irradiation has attracted extensive attentions and great effort has been devoted to augment its catalytic efficacy. In this work, we synthesized a p-n heterojunction, NiFe 2 O 4 /ZnIn 2 S 4 , to enhance the carrier migration rate and explained the intrinsic mechanism by density functional theory. When the heterojunction was formed, carriers traversed from the n-type NiFe 2 O 4 to the p-type ZnIn 2 S 4 , instigating the emergence of a built-in electric field to facilitate the separation of carriers. 2 %-NiFe 2 O 4 /ZnIn 2 S 4 exhibited excellent photocatalytic efficiency in tetracycline (TC) degradation and total organic carbon (TOC) removal. Compared to pure ZnIn 2 S 4 and NiFe 2 O 4 , the TC degradation rates of 2 %-NiFe 2 O 4 /ZnIn 2 S 4 were 2.0 times and 16.9 times higher, respectively. Additionally, 2 %-NiFe 2 O 4 /ZnIn 2 S 4 had a saturation magnetization intensity of 3.05 emu/g, allowing for rapid recovery of the catalyst under a magnetic field. Superoxide radicals (O 2 - ) and holes (h + ) were the primary active species driving the degradation process. Furthermore, potential reaction pathways of tetracycline in this photocatalytic process were determined and bioconcentration factor and developmental toxicity of the intermediate products were accessed. This work held great potentials for wastewater treatment and provided a pathway for the development of magnetic recyclable photocatalysts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The commercial application of lithium-sulfur batteries is primarily impeded by the constant shuttling of soluble polysulfides and sluggish redox kinetics. Nowadays, the discovery of the heterojunction, which combines materials with diverse properties, offers a new perspective for overcoming these obstacles. Herein, a functional coating separator for the lithium-sulfur battery is designed using a MnO 2 -ZnS p-n heterojunction with a spontaneous built-in electric field (BIEF). The MnO 2 nanowire provides suitable adsorption capacity for polysulfides, while the abundant reactive sites brought by ZnS ensure efficient conversion. Moreover, the BIEF significantly facilitates the migration of electrons and polysulfides at the MnO 2 -ZnS interface, enabling a smooth "adsorption-diffusion-conversion" reaction mechanism. By serving as both the adsorption module and catalytic sites, this BIEF allows batteries utilizing separators modified with MnO 2 -ZnS heterojunction to achieve an impressive initial capacity of 1511.1 mAh g -1 at 0.1C and maintain a capacity decay rate of merely 0.048% per cycle at 2.0C after 1000 cycles. Even when increasing sulfur loading to 9.4 mg cm -2 in lean electrolyte (5.4 μL mg -1 ), the battery still exhibits an ultrahigh areal capacity of 6.0 mAh cm -2 after 100 cycles., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Surface reconstruction of electrocatalysts is an effective strategy to modulate the space charge distribution to enhance the electrocatalytic activity. The p-n heterostructured FeP/CoP-2D octagonal nanoplates were successfully constructed by cation-exchange method. The space charge effect caused by the p-n heterojunction accelerated the electron transfer, optimized the electronic structure, and improved the activity of the active sites during the oxygen evolution reaction process. As a result, FeP/CoP-2D required only 247 mV overpotential to achieve a current density of 10 mA cm -2 with a Tafel slope as low as 68 mV dec -1 . Density-functional theory calculations confirmed that the construction of p-n heterojunctions can enhance the adsorption of *OH in the active centers and optimize the Gibbs free energy of the OER reaction. This study provides an effective and feasible strategy for constructing p-n heterojunctions to modulate the space charge state for optimizing the OER performance of electrocatalysts., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

To enhance the efficiency of photocatalytic H 2 evolution, numerous methods are employed by increasing the utilization of photogenerated charge carriers (PCCs), including catalyst design, defect regulation, and selection of suitable H + resources. Using self-assembly method, CoWO 4 /Zn x Cd 1-x S with p-n heterojunction was synthesized. Although CoWO 4 (CW) cannot produce H 2 under visible light irradiation, it can provide photogenerated electrons (e - ) to Zn 0.3 Cd 0.7 S (ZCS), and largely increase the photocatalytic activity of ZCS. The optimal CW/ZCS composite can reach 15.58 mmol·g -1 ·h -1 , which is 45.8 and 24.3 times higher than the values of the pure CdS and ZCS, respectively. The largely enhanced photocatalytic H 2 production is attributed to the Zn vacancies (V Zn ), p-n heterojunction, and p-chlorobenzyl alcohol (Cl-PhCH 2 OH) as the H + source of H 2 production. V Zn on the ZCS surface as the capture center of photogenerated holes (h + ), can regulate the carrier distribution, which results in more photogenerated e - and less generated h + . The combination of p-n heterojunction and V Zn can enhance the separation and transfer efficiency of PCCs, and effectively inhibit the recombination of charge carriers. To further improve the utilization rate of PCCs, the photocatalytic H 2 evolution is proceeded by Cl-PhCH 2 OH oxidation in N,N-dimethylformamide solution, with 4-chlorobenzaldehyde (Cl-PhCHO) generated. The separated photogenerated e - and h + both participated in the redox reaction of H + reduction and Cl-PhCH 2 OH oxidation, considering that the amount of H 2 and Cl-PhCHO products are close to 1:1. This work not only facilitates the separation and transfer of PCCs, but also provides directions for the design of efficient photocatalysts and H 2 evolution in the organic phase., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Semiconductor gas sensing materials with specific crystal facets exposure have attracted researchers' attention recently. However, related research mainly focuses on single metal oxide semiconductor. The research on crystal facets designing of semiconductor p-n heterojunction is still highly challenging. Herein, based on NiCo 2 O 4 octahedral nanocrystals with high-energy {111} crystal facets as substrate, Fe 2 O 3 nanorods with {001} crystal facets were decorated to obtain a facet-specific NiCo 2 O 4 /Fe 2 O 3 p-n heterojunction. The p-n heterojunction showed promising triethylamine sensing properties with a high response of 70 (R a /R g , 100 ppm) at 300 °C, which was about 57 and 10 times higher than that of pristine NiCo 2 O 4 and Fe 2 O 3 , respectively. Theoretical calculation suggested that the electronic coupling effect formed by d-orbitals of Co-Fe in heterojunction strengthened the influence on the orbitals of N site in triethylamine, which improved the triethylamine adsorption and interface charge transfer. The results indicate that crystal facets designing of NiCo 2 O 4 and Fe 2 O 3 can achieve synergistic optimization of surface/interface characteristics of p-n heterojunction, thereby achieving a comprehensive improvement in gas sensing performance. This study not only provides a high performance triethylamine sensing material, but also greatly enriches the gas sensing mechanism of p-n heterojunction at the atomic and electronic levels., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Heterojunctions have been proved to be the promising photocatalysts for hazardous contaminants removal, but the inferior interfacial contact, low carrier mobility and random carrier diffusion seriously hamper the photoactivity improvement of the conventional heterojunctions. Herein, SO chemically bonded p-n oriented heterostructure is fabricated via selectively anchoring of p-type Ag 2 S nanoparticles on the lateral facet of n-type Bi 4 TaO 8 Cl nanosheet. Such a p-n heterojunction engineering on specific facet of Bi 4 TaO 8 Cl semiconductor derives ingenious double internal electric field (IEF), which not only effectively creates the spatially separated oxidation and reduction sites, but also delivers the powerful driving forces for impactful spatial directed photocarrier transfer along the cascade path. Additionally, our experimental and theoretical analyses jointly signify that the interfacial SO bond could serve as an efficient atomic-level interfacial channel, which is conducive to encouraging the vectorial charge separation and migration kinetic. As a result, the Ag 2 S/Bi 4 TaO 8 Cl oriented heterojunction exhibits significantly enhanced visible light driven photocatalytic redox ability for tetracycline oxidation and hexavalent chromium reduction than those of single component and the traditional random/mixed heterojunctions. This study could provide a deeper insight into the synergistic effects of multi-IEF modulation and interfacial chemical bond bridging on optimizing the photogenerated carrier behaviors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Studying interfacial charge transfer is of great significance for the preparation of electrocatalysts with high activity for the hydrogen evolution reaction (HER). Particularly, exploring the in-depth catalytic mechanisms and facile fabrication methods of narrow bandgap metal phosphides remains worthwhile. This work successfully combined catalytically inert n-type Nb 2 O 5 with p-type CoP to prepare a p-n heterojunction (CoP-Nb 2 O 5 ). The self-supporting heterojunction was fabricated by gas-phase phosphorization of the Co(OH) 2 -Nb 2 O 5 precursor obtained through hydrothermal-electrodeposition strategy. By analyzing the electronic and band structures of CoP and Nb 2 O 5 , it was found that there exists a built-in electric field (BEF) in the heterojunction. This BEF can modulate the electronic structure of CoP at the interface, enhance its intrinsic activity and accelerate charge migration. The subsequent experimental results also demonstrate that Nb 2 O 5 can significantly enhance the activity and stability of CoP. Our findings can serve as a novel perspective on the application of p-n heterojunction in the field of energy storage and conversion., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Hollow structure hybrids have gained considerable attention for their ability to reduce CO 2 owing to their rich active sites, high gas adsorption ability, and excellent light utilization capacity. Herein, a template-engaged strategy was provided to fabricate copper sulphide@cerium dioxide (CuS@CeO 2 ) p-n heterojunction hollow cube photocatalysts using Cu 2 O cubes as a sacrificial template. The sequential steps of loading of CeO 2 nanolayer, sulfidation, and etching reaction facilitate the formation of CuS@CeO 2 p-n heterojunction hollow cubes. Compared with the single CuS, CeO 2 , and their physical mixture, the CuS@CeO 2 p-n heterojunction hollow cube photocatalyst expresses a higher performance toward photocatalytic CO 2 reduction under solid-gas reaction conditions due to the faster separation of photogenerated charges. The further enhanced performance of CuS@CeO 2 p-n heterojunction hollow cubes was achieved by decorating pt nanoparticles due to the fact that Pt nanoparticles had a high electron affinity and CO 2 adsorption capacity, and the highest CO and CH 4 yields of the optimized hybrid reached 195.8 μmol g -1 h -1 and 19.96 μmol g -1 h -1 , respectively. This work might provide a strategy for designing and synthesizing efficient hollow heterostructured photocatalysts for solar energy conversion and utilization., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Selective photocatalysis to simultaneously produce sustainable hydrogen and value-added chemicals from biomass or biomass derivates is attracting extensive investigations. However, the lack of bifunctional photocatalyst greatly limits the possibility to realize the "one stone kills two birds" scenario. Herein, anatase titanium dioxide (TiO 2 ) nanosheets are rationally designed as the n-type semiconductor, combining with nickel oxide (NiO) nanoparticles, the p-type semiconductor, resulting in the formation of a p-n heterojunction structure. The shorten charge transfer path and the spontaneous formation of p-n heterojunction endow the photocatalyst with efficient spatial separation of photogenerated electrons and holes. As a result, TiO 2 accumulates electrons for efficient hydrogen generation while NiO collects holes to selectively oxidize glycerol into value-added chemicals. The results showed that by loading 5% nickel into the heterojunction caused a remarkable rise in the generation of hydrogen (H 2 ). The combination of NiO-TiO 2 created 4000 µmolh -1 g -1 of H 2 , which is 50% greater than the H 2 production from pure nanosheet TiO 2 and 63 times more than the H 2 production from commercial nanopowder TiO 2 . Then, by changing loading amount of Ni, it is found that when 7.5 % of Ni is loaded the highest amount of hydrogen production achieved, 8000 µmolh -1 g -1 . By employing best sample (S3), 20 % of glycerol converted to value added products, glyceraldehyde and dihydroxyacetone. The feasibility study revealed that glyceraldehyde generates the largest portion of yearly earnings at 89%, while dihydroxyacetone and H 2 account for 11% and 0.03% of the annual revenue, respectively. This work provides a good example to simultaneously produce green hydrogen and valuable chemicals with the rational design of dually functional photocatalyst., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The construction of heterojunctions is commonly regarded as an efficient way to promote the production of hydrogen via photocatalytic water splitting through the enhancement of interfacial interactions. The p-n heterojunction is an important kind of heterojunction with an inner electric field based on the different properties of semiconductors. In this work, we reported the synthesis of a novel CuS/NaNbO 3 p-n heterojunction by depositing CuS nanoparticles on the external surface of NaNbO 3 nanorods, using a facile calcination and hydrothermal method. Through the screening of different ratios, the optimum hydrogen production activity reached 1603 μmol·g -1 ·h -1 , which is much higher than that of NaNbO 3 (3.6 times) and CuS (2.7 times). Subsequent characterizations proved semiconductor properties and the existence of p-n heterojunction interactions between the two materials, which inhibited the recombination of photogenerated carriers and improved the efficiency of electron transfer. This work provides a meaningful strategy to utilize the p-n heterojunction structure for the promotion of photocatalytic hydrogen production., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The construction of a p-n heterojunction structure is considered to be an effective method to improve the separation of electron-hole pairs in photocatalysts. A series of ZnIn 2 S 4 /CoFe 2 O 4 (ZIS/CFO) photocatalysts with p-n heterojunctions were prepared via a method involving ultrasonication and calcination. The synthesized photocatalysts were tested and analyzed via various testing techniques, and their hydrogen evolution rates were evaluated. Compared with pure ZIS, ZIS/CFO with different mass ratios of CFO to ZIS showed improved photocatalytic hydrogen production performance, and the optimal photoactivity showed a nearly 12-fold increase, which can be attributed to the formation of p-n junctions and the formed internal electric field, accelerating the separation of electron-hole pairs and effectively improving the photocatalytic hydrogen evolution rate. The excellent stability of the ZIS/CFO composite was proven by three cycle experiments. In addition, the ZIS/CFO composite also possessed excellent magnetic properties to realize facial magnetic recoverability. This work paves the way for the design and preparation of magnetically recoverable p-n heterojunction photocatalysts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Fe 2 O 3 is a promising n-type semiconductor as the photoanode of photoelectrochemical water-splitting method due to its abundance, low cost, environment-friendly, and high chemical stability. However, the recombination of photogenerated holes and electrons leads to low solar-to-hydrogen efficiency. In this work, to overcome the recombination issue, a p-type semiconductor, CuO, is introduced underneath the γ-Fe 2 O 3 to synthesize γ-Fe 2 O 3 /CuO on the FTO substrate. Along with the formation of p-n heterojunction, CuFe 2 O 4 is in situ generated at the interface of γ-Fe 2 O 3 and CuO. The existence of Cu 2 O in CuO and CuFe 2 O 4 promotes the charge transfer from CuO to γ-Fe 2 O 3 and within CuFe 2 O 4 , respectively, resulting in creating an internal electric field in γ-Fe 2 O 3 /CuO and leading to the conduction band of CuO bending up and γ-Fe 2 O 3 bending down. Additionally, Cu(II) in CuFe 2 O 4 contributes to fast electron capture. Consequently, the charge transfer efficiency and charge separation efficiency of photo-generated holes are promoted. Hence, γ-Fe 2 O 3 /CuO exhibits an enhanced photocurrent density of 13.40 mA cm -2 (1.9 times higher than γ-Fe 2 O 3 ). The photo corrosion resistance of CuO is dramatically increased with the protection of CuFe 2 O 4 , resulting in superior high chemical stability, i.e. 85% of the initial activity remains after a long-term test., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

It is an effective way to improve the photocatalytic hydrogen evolution activity by constructing a unique structure and tuning the morphology of catalysts. On the one hand, ZIF-67 was used as a precursor to prepare Co 3 O 4 derivatives with different morphologies [Co 3 O 4 (Porous Polyhedron) and Co 3 O 4 db (Hollow Double-Shelled Polyhedron)]. The hollow polyhedron have the advantages of large specifie surface area, low density, stable three-dimensional spatial structure and excellent electron transport channels, which provide great advantages for the enhancement of photocatalytic activity in photocatalytic reactions. On the flip side, p-type Co 3 O 4 polyhedron and n-type Zn 0.5 Cd 0.5 S nanoparticles are successfully coupled to construct a p-n heterojunction, which accelerated the transfer and separation of electrons and holes, thus enhancing the photocatalytic hydrogen production efficiency. Therefore, the composite catalyst (Zn 0.5 Cd 0.5 S-Co 3 O 4 db-20 %) exhibits excellent hydrogen evolution activity (33885 μmol·h -1 ·g -1 ), which is 9.17 times that of pure Zn 0.5 Cd 0.5 S (3695 μmol·h -1 ·g -1 ) and 1.21 times that of Zn 0.5 Cd 0.5 S-Co 3 O 4 -20 % (27903 μmol·h -1 ·g -1 ). This work provides a new idea for tuning the photocatalytic morphology to enhance the hydrogen evolution activity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The photoelectrocatalytic (PEC) water splitting efficiency of semiconductor photoelectrodes is mainly limited by the effective separation and transfer of photogenerated charges. Zinc indium sulfide-cuprous oxide (ZnIn 2 S 4 -Cu 2 O) p-n heterojunction is constructed to enhance the PEC properties of ZnIn 2 S 4 . The nickel hydroxide iron oxide (NiFeOOH) layer on the surface of the heterojunction can be used as a hole depletion layer under the induction of plasmon resonance of the most surface silver (Ag) (the holes transferred from Cu 2 O valence band to NiFeOOH layer can be excited by Ag to produce hot electron consumption, which makes the last remaining hot holes participate in the water oxidation reaction) to further promote the carrier separation and transfer. The results exhibit that ZnIn 2 S 4 /Cu 2 O/NiFeOOH/Ag photoelectrode with dramatically enhanced photocurrent density of 1.22 mA/cm 2 at 1.23 V versus the reversible hydrogen electrode (V RHE ), which is 9.4 times higher than the pure ZnIn 2 S 4 . This work provides a promising concept to design photoelectrodes efficiently in PEC water splitting., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Aiming at the drawbacks of hematite like poor conductivity and tardy oxidation kinetics, herein, we utilized dual dopants in the bulk and surface to ameliorate the situation. Specifically, doping optimal amount of Zr 4+ in the hematite (Zr:Fe 2 O 3 ) enhances the conductivity of hematite due to the higher charge carrier density. Further, F:FeOOH could form p-n heterojunction in bulk where a potential barrier is built up that repels electrons but prompts holes transferring to F:FeOOH for water oxidation. What's more, the high electronegative of F - would withdraw electron from the Fe site in FeOOH, and the enhanced positive electricity of Fe 3+ is beneficial for adsorption of OH - as well as enhance the conductivity of FeOOH to expedite holes transfer. As a result, the composite photoanode (F:FeOOH/Zr:Fe 2 O 3 ) shows a 3.25-times enhanced photocurrent density comparing with α-Fe 2 O 3 . The special designation employs ultrathin F:FeOOH to act as both p-type semiconductor and efficient co-catalyst, avoiding redundant layer that would extend the migration distance of holes. On the top of that, the dual modification approach provides an extensive prospect for the further application of hematite., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

The rapid recombination of photoinduced charge carriers and low selectivity are still challenges for the CO 2 photoreduction. Herein, we proposed that ZIF-67-derived Co 3 O 4 hollow polyhedrons (CoHP) were embedded into NaCl-template-assisted synthesized 3D graphitic carbon nitride (NCN), subsequently, loading Ag by photo-deposition as efficient composites (CoHP@NCN@Ag) for CO 2 photoreduction. This integration simultaneously constructs two heterojunctions: p-n junction between Co 3 O 4 and g-C 3 N 4 and metal-semiconductor junction between Ag and g-C 3 N 4 , in which Co 3 O 4 and Ag serve as hole (h + ) trapping sites and electron (e - ) sinks, respectively, achieving spatial separation of charge carriers. The donor-acceptor structure design of NCN realize a good photogenerated e - -h + separation efficiency. The mesoporous structure of hollow Co 3 O 4 facilitate gas-diffusion efficiency, light scattering and harvesting. And the introduction of plasmonic Ag further strengthens the light-harvesting and charge migration. Benefiting from the rational design, the optimized ternary heterostructures exhibit a high CO 2 -CO yield (562 μmol g -1 ), which is about 4-fold as high as that of the NCN (151 μmol g -1 ). Moreover, the conjectural mechanism was systematically summarized. We hope this study provides a promising strategy for designing efficient g-C 3 N 4 systems for the CO 2 photoreduction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Here, cobalt-doped copper bismuth oxide (Co-CuBi 2 O 4 ) was synthesized via a facile hydrothermal method for photoelectrocatalytic (PEC) hydrogen production. The results disclosed that the 5% Co-doped CuBi 2 O 4 has better PEC activity which is ∼3 fold higher than pristine CuBi 2 O 4 . The doping of cobalt in CuBi 2 O 4 improves the interfacial charge transfer at an electrode/electrolyte interface and reduces the recombination rate of photogenerated electron-hole pairs. This higher performed 5% Co-doped CuBi 2 O 4 photocathode further modified with TiO 2 -P25 to form a Co-CuBi 2 O 4 /TiO 2 p-n heterojunction. This Co-CuBi 2 O 4 /TiO 2 photocathode displayed a photocurrent density of 330 μA cm -2 at +0.5 V vs. RHE which was ∼2 fold higher than Co-CuBi 2 O 4 . Because this p-n junction affords inner electric field in the space charge region that helps for further minimization of electron-hole recombination, which facilitate efficient charge separation and transport thereby enhance the PEC water reduction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Bismuth titanate (Bi 12 TiO 20 ) with unique sillenite structure has been shown to be an excellent photocatalyst for environmental remediation. However, the narrow light-responsive range and rapid recombination of photoinduced electrons-holes limit the photocatalytic performance of Bi 12 TiO 20 . To overcome the limitations, a practical and feasibleway is to fabricate heterojunctions by combining Bi 12 TiO 20 with suitable photocatalysts. Here, using a facile chemical precipitation method, a novel and hierarchical core-shell structure of n-Bi 12 TiO 20 @p-BiOI (BTO@BiOI) heterojunction was rationally designed and synthesized by loading BiOI nanosheets on BTO nanofibers. The constructed BTO@BiOI composites exhibited significant charge transfer ability due to the synergistic effects of the built-in electric field between BTO and BiOI as well as close interfacial contacts. In addition, the narrow bandgapcharacteristics of the BiOI led to wide light absorption ranges. Therefore, the BTO@BiOI heterojunction exhibited an improved photocatalytic performance under visible light irradiation. The NO removal efficiency of optimal BTO@BiOI was 45.7%, which was significantly higher compared tothat of pure BTO (3.6%) or BiOI (23.1%). Moreover, the cycling experiment revealed that BTO@BiOI composite has a good stability and reusability. The possible mechanism of photocatalytic NO oxidation over BTO@BiOI was investigated in detail., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Developing photocatalysts that are inexpensive and efficient in degrading pollutants are essential for environmental remediation. Herein, a novel system of perylene diimide (PDI)/CuS p-n heterojunction was synthesized by a two-step self-assembly strategy for removal of tetracycline in waste water. Results showed that PDI/CuS-10% exhibited highest photocatalytic behavior. The apparent rate constants for tetracycline (TC) degradation for the blend were 5.27 and 2.68 times higher than that of CuS or PDI, respectively. The enhancement of photocatalytic activity was mainly attributed to the π-π stacking and p-n junction, which can accelerate the separation of the photo-generated h + -e - pairs. Besides, the light absorption of PDI/CuS from 800 to 200 nm was significantly enhanced and the absorption edge even reached the near-infrared region, which also played an important role in providing desired photocatalytic properties. Surprisingly, PDI/CuS could maintain high catalytic activity even after 5 cycles under simulated conditions, indicating that the composite had high potential for practical applications. Owing to high efficiency, low cost and wide application range, the PDI/CuS nanocomposites are promising candidates for environmental remediation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The development of the efficient photocatalysts with improved photoexcited charge separation and transfer is an essential for the effective photocatalytic H 2 generation using light energy. So far, owing to the unique properties and characteristics, the transition metal phosphides (TMPs) have been proven to be high performance co-catalysts to replace some of the classic precious metal materials in the photocatalytic water splitting. In the present work, we report a novel copper phosphide (Cu 3 P) as a co-catalyst to form a well-designed fabricated photocatalyst with blacktrumpet mushroom-like ZnS semiconductor for the first time. The synthesis of Cu 3 P/ZnS consists of two-step hydrothermal and ball milling methods. The physical properties of the materials so prepared were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectroscopy (UV-DRS), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analyses. In order to study the role of Cu 3 P, electrochemical impedance spectroscopy (EIS) measurements were used to investigate the photogenerated charge properties of ZnS. The experiments of photocatalytic production of H 2 confirm that the Cu 3 P co-catalysts effectively promote the separation of photogenerated charge carriers in ZnS, and consequently enhance the H 2 evolution activity. The 3% Cu 3 P/ZnS sample delivers the highest catalyst activity and the consistent H 2 evolution rate is14,937 µmol h -1 g -1 cat , which is 10-fold boosted compared to the pristine ZnS. The stability of the catalyst was tested by reusing the used 3% Cu 3 P/ZnS photocatalyst in five consecutive runs, and their respective activity in the H 2 production activity was evaluated. A possible mechanism is proposed and discussed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

This work was designed to prepare a novel NiS/KNbO 3 p-n heterojunction composite for efficient photocatalytic nitrogen fixation under simulated sunlight. The NiS/KNbO 3 photocatalyst was prepared through a two-step hydrothermal method. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy analyses proved that NiS nanoparticles were closely decorated on the surface of KNbO 3 nanorods, to facilitate the migration of electrons between the two semiconductors. Mott-Schottky analysis indicated that the Femi level of KNbO 3 is higher than that of NiS. Thus, the electron migration from KNbO 3 to NiS occurs naturally. This migration elevates the band potential of NiS, makes NiS/KNbO 3 form a type-II photocatalyst, and generates an internal electric field in the composite. The synergetic effect of the internal electric field and the type-II band structure endows NiS/KNbO 3 with high efficiency in the spatial separation of photogenerated electron-hole pairs, verified by electrochemical impedance spectroscopy and transient photocurrent experiments. Therefore, NiS/KNbO 3 presents good efficiency in photocatalytic N 2 reduction with an NH 3 production rate of 155.6 μmol·L -1 ·g -1 ·h -1 , which is 1.9 and 6.8 times higher than those of KNbO 3 and NiS, respectively. UV-visible diffuse reflectance spectroscopy and N 2 -adsorption experiments were also performed to investigate the effect of light absorption and surface area on the photocatalytic reaction. Nevertheless, compared with the great promotion effect in charge separation, the contribution of the two factors can be ignored., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Photoreduction of CO 2 to valuable fuels with semiconductor photocatalysts is a good solution to the problems of global warming and energy crisis. Creation of hybrid nanomaterials with hierarchical and/or heterojunction structures is beneficial to develop efficient photocatalysts for CO 2 reduction. Herein we present a convenient method to obtain a hybrid photocatalyst consisting of MnS and In 2 S 3 nanosheets with assembled hierarchical structures through using Mn 2+ -loaded MIL-68(In) submicro-rods as templates. Owing to the dispersive Mn 2+ and In 3+ ions in templates, numerous small p-n heterojunctions of MnS/In 2 S 3 could be simultaneously produced in each hierarchical particle. The p-type MnS and n-type In 2 S 3 with an original type II band alignment can create a stronger built-in electric field after the formation of p-n heterojunctions, which is favorable for charge separation and migration to catalyst surface. The prepared MnS/In 2 S 3 heterojunctions show an 4-fold higher photocatalytic activity toward CO 2 reduction than pristine MnS and In 2 S 3 . The MnS/In 2 S 3 hierarchical structures were well characterized and their working mechanism was explored. This work demonstrates a facile strategy to create efficient hybrid photocatalysts with both hierarchical structures and p-n heterojunctions for photocatalytic applications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

During the past several years, transition metal compounds have shown high activity in the field of photocatalysis. Therefore, the MoSe 2 @Co 3 O 4 with excellent photocatalytic properties through simple hydrothermal and physical mixing methods was prepared. This composite material was composed of n-type semiconductor MoSe 2 and p-type semiconductor Co 3 O 4 . After optimizing the loading of Co 3 O 4 , the optimal hydrogen production can reached 7029.2 μmol g -1 h -1 , which was 2.34 times that of single MoSe 2 . In addition, some characterization methods were used to explore the hydrogen production performance of the composite catalyst under EY sensitized conditions. Among them, the UV-vis diffuse reflectance spectra suggests that MoSe 2 @Co 3 O 4 exhibits stronger visible light absorption performance than the single material. Fluorescence performance and photoelectrochemical characterization experiments further prove that, the special structure formed by MoSe 2 and Co 3 O 4 and the existence of p-n heterojunction effectively accelerate the separation and transfer of carriers meanwhile inhibit the recombination probability of electron-hole pairs. Combined with other characterizations such as XRD, XPS, SEM and BET, the possible hydrogen production mechanism was proposed., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

When two semiconductors are electronically coupled, their photocatalytic performance can be greatly enhanced. Herein, we formed a heterostructure between Cu 2 O and SnS 2 /SnO 2 nanocomposite using a solvothermal reactor, which reduced CO 2 by H 2 O at ambient conditions to produce CO, H 2, and CH 4 . With inclusion of Cu 2 O, apparent quantum yield, a measure of photoactivity, has increased from 7.16% to 8.62%. Also, the selectivity of CH 4 over CO was approximately 1.8-times higher than that of SnS 2 /SnO 2 . Interestingly, the as-synthesized catalysts were able to fix N 2 to NH 3 under light illumination at ambient conditions. Dissecting the mechanism into basic steps, it is shown that oxygen vacancies within the catalysts act as trapping sites for photo-induced charge carriers which strongly influenced the reactivity and selectivity of product. Additionally, oxygen vacancies act as active sites to chemisorb nitrogen molecules, which follow associative steps to generate NH 3 . In absence of sacrificial agent, the NH 4 + generation rate was66.35μmol.g -1 h -1 for Cu 2 O/SnS 2 /SnO 2 , which is 1.9-fold higher than SnS 2 . Formation of a p-n heterojunction between Cu 2 . Formation of a p-n heterojunction between Cu 2 O and SnS 2 /SnO 2 nanocomposite offered favorable photoreductive potentials and high stability, mainly owing to their intimate interfacial contact. The results clearly illustrate a promising strategy to use oxygen vacancies rich heterostructure for wide application in photocatalysis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Enriching the active sites of catalysts and artificially regulating the directional migration of photogenerated carriers are effective means to improve the catalytic activity of photocatalysts. In this work, polyvinylpyrrolidone (PVP) is used as the morphological modifier to prepare MoS x with three-dimensional (3D) nanoflower structure. Compared with two-dimensional (2D) MoS x nanosheets, three-dimensional nanoflower structure weakens the van der Waals force between nanosheets and inhibits the stacking between layers, thus exposing the high-density active sites of MoS x nanoflower. The CoWO 4 nanoparticles are successfully anchored to MoS x by in-situ growth, forming the MoS x /CoWO 4 p-n heterojunction photocatalyst. The high photosensitivity of MoS x increases the utilization of MoS x /CoWO 4 p-n heterojunction to visible light. The unique 3D nanoflower structure of MoS x results in that CoWO 4 nanoparticles are dispersed well on the surface of MoS x , which prevents CoWO 4 agglomeration. Based on the high efficiency of charge separation, abundant active sites and excellent property of visible light response, the hydrogen evolution rate of MoS x /CoWO 4 -40 reached 9414.4 μmol g -1  h -1 ., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

To develop a high sensitive and low temperature NO 2 gas sensor, the novel BiVO 4 /Cu 2 O heterojunctions were synthesized by a modified metal organic decomposition method to decorate BiVO 4 nanoplates using Cu 2 O nanoparticles for enhancement of BiVO 4 sensing performance to NO 2. The structure and morphology of BiVO 4 , Cu 2 O and BiVO 4 /Cu 2 O composites were characterized by XRD, SEM and TEM spectra. The results indicate that the BiVO 4 /Cu 2 O heterojunctions are composed of monoclinic BiVO 4 nanoplates with the thickness about 1.0-1.2 μm and 30-40 nm diameters of cubic Cu 2 O nanoparticles. The gas-sensing tests display that the composite exhibits rapid and linear responses to low concentration NO 2 (from 100 ppb to 8.0 ppm), the highest response reaches 4.2 towards 4 ppm NO 2 at 60 °C and relative humidity of 28.3%, which is more than 2 times of pure BiVO 4 at the same condition. The enhanced sensing properties benefit from the novel p-n heterojunction between BiVO 4 and Cu 2 O, which forms a depletion layer at the interface, leading to resistance increase of composites in NO 2 . The work demonstrates the as-synthesized BiVO 4 /Cu 2 O is a promising sensing material to detect NO 2 gas., Competing Interests: Declaration of Competing Interest The authors declared that there is no conflict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Charge carrier separation of photocatalysts can be accelerated by p-n heterojunctions and surface defect engineering. Here, novel silver silicate/ceria p-n heterojunction photocatalysts with a hierarchical flower-like structure were successfully synthesized through an in situ deposition-precipitation method in which p-type silver silicate (Ag 6 Si 2 O 7 ) nanoparticles were evenly decorated on the sheets of n-type ceria (CeO 2 ) nanoflowers prepared via an ice-bath coprecipitation process. Mott-Schottky plots and morphological studies indicated that p-n heterojunctions were constructed between Ag 6 Si 2 O 7 and CeO 2 . This led to the generation of abundant surface defects (Ce 3+ ions or oxygen vacancies) in the heterojunctions as confirmed by XPS and Raman. The photocatalytic properties are markedly improved under visible light irradiation and can be regulated by the Ag 6 Si 2 O 7 content in the composites. The sample with 40 wt% Ag 6 Si 2 O 7 loading had optimal photocatalytic elimination efficiency for the colorless contaminant tetracycline, the cationic dye rhodamine B, and the anionic dye methyl orange. As evidenced by various characterization techniques, the decoration of Ag 6 Si 2 O 7 nanoparticles can promote the formation of a surface defect structure, increase visible light harvesting, and improve the separation of charge carriers driven by the internal electric field established between two semiconductors, thus leading to a remarkably enhanced photocatalytic activity. This work offers a reliable strategy for designing efficient p-n heterojunctions for photocatalytic applications in energy and the environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Visible-light harvesting ability and charge separation efficiency are two pivotal factors for the design and construction of photocatalysts with an efficient ability for degrading toxic pollutants. Herein, visible-light-driven (VLD) BiOBr/BiOCOOH p-n heterojunction photocatalysts were prepared via an in-situ anion-exchange route. Through controlling the addition of KBr, we synthesized a series of BiOBr/BiOCOOH p-n heterojunctions with a different BiOBr loading. During the process, BiOBr production and homogeneous deposition on BiOCOOH with close interfacial interactions were realized by employing BiOCOOH microspheres as the self-sacrificing template. Compared to bare BiOBr and BiOCOOH, such p-n heterojunctions displayed dramatically strengthened performance in decomposing the industrial dye (rhodamine B, RhB) and antibiotic (tetracycline chloride, TC) under the irradiation of visible light. Among them, BiOBr/BiOCOOH p-n heterojunction with a BiOBr/BiOCOOH theoretical molar ratio of 0.6/0.4 (0.6Br-Bi) achieved the highest performance. Moreover, 0.6Br-Bi showed a good durability, indicating BiOBr/BiOCOOH p-n heterojunction possessed an excellently stable photocatalytic activity. Such an efficient and stable photocatalytic performance was mainly due to the formation of p-n heterojunctions which can profoundly improve the visible-light absorption and significantly depress the recombination of charge carriers. Trapping experiments and ESR tests verified that superoxide free radicals (O 2 - ) played a significant role in RhB degradation. This research affords a promising p-n heterojunction catalyst for wastewater treatment.+ ) played a significant role in RhB degradation. This research affords a promising p-n heterojunction catalyst for wastewater treatment., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Construction of Schottky junction or p-n heterojunction is admitted as an effective way for improving the separation of photo-induced carriers through its built-in electric field. In this work, fabrication of cooperative Schottky and p-n (SPN) heterojunction has been realized by intercalating metal Ni into a NiO/TiO 2 p-n junction, forming a NiO/Ni/TiO 2 Sandwich-like heterojunction. The special heterostructure was confirmed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and the high-resolution transmission electron microscopic (HRTEM), Brunauer Emmett Teller (BET). After a serial of contrast experiments with solo Schottky or p-n junction, it was found that the electron-hole separation in this NiO/Ni/TiO 2 SPN heterojunction was enhanced through charge transfer channel, and it was also in accordance with their related optical and photoelectrical properties characterizations, such as photoluminescence (PL) spectrum and UV-Vis diffused reflectance spectra. In the following photocatalytic water splitting process under visible light, the hydrogen generation rate of NiO/Ni/TiO 2 reached up to 4653 μmol h -1 g -1 , which was 10.2, 6.7 and 2.3 times of those of TiO 2 (457 μmol h -1 g -1 ), Ni/TiO 2 (691 μmol h -1 g -1 ) with a Schottky junction and NiO/TiO 2 (2059 μmol h -1 g -1 ) with a p-n junction, respectively. This SPN heterojunction with excellent photo-induced electron-hole separation ability opens a new window to exploring photocatalyst for water splitting., (Copyright © 2018 Elsevier Inc. All rights reserved.)

A p-n heterojunction film of Cu 2 O/α-Fe 2 O 3 was constructed by electrodepositing p-type Cu 2 O microcubes on liquid phase deposited film of n-type α-Fe 2 O 3 . The surface morphology, the crystal phase and composition of Cu 2 O/α-Fe 2 O 3 heterojunction film were characterized by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The enhanced absorption in the visible light region was observed in UV-visible diffuse reflectance spectra. Meanwhile, an efficiently improved separation and faster transfer of photogenerated electrons and holes were revealed by photoluminescence spectra and electrochemical impedance spectra. The Cu 2 O/α-Fe 2 O 3 p-n heterojunction was applied to photoelectrocatalytic degradation of oxytetracycline at a bias potential of +0.5 V under visible light illumination. After 60-min photoelectrocatalytic treatment, 73.3% of oxytetracycline was removed and the degradation rate constant reached 2.14 × 10 -2  min -1 . Moreover, the crystal phases and compositions for the used and fresh Cu 2 O/α-Fe 2 O 3 films were studied, and a possible photoelectrocatalytic mechanism was proposed., (Copyright © 2018 Elsevier Inc. All rights reserved.)

P-type bismuth oxychloride (p-BiOCl) nanosheets were uniformly grown on n-type zinc ferrite (n-ZnFe 2 O 4 ) electrospun nanofibers via a solvothermal technique to form hierarchical heterostructures of p-BiOCl/n-ZnFe 2 O 4 (p-BiOCl/n-ZnFe 2 O 4 H-Hs). The density and loading amounts of the BiOCl nanosheets with exposed {0 0 1} facets were easily controlled by adjusting the reactant concentration in the solvothermal process. The p-BiOCl/n-ZnFe 2 O 4 H-Hs exhibited enhanced visible-light photocatalytic activities for the degradation of Rhodamine B (RhB). The apparent first-order rate of the p-BiOCl/n-ZnFe 2 O 4 H-Hs and its normalized constant were about 12.6- and 8-fold higher than pure ZnFe 2 O 4 nanofibers. This suggests that both the improved charge separation efficiency from the uniform p-n heterojunctions and the enlarged active surface sites from the hierarchical structures increase the photocatalytic performances. Furthermore, the p-BiOCl/n-ZnFe 2 O 4 H-Hs could be efficiently separated from the solution with an external magnetic field via the ferromagnetic behavior of ZnFe 2 O 4 nanofibers. The magnetic p-BiOCl/n-ZnFe 2 O 4 H-Hs with enhanced visible-light photocatalytic performances might have potential applications in water treatment., (Copyright © 2018. Published by Elsevier Inc.)

Constructing novel and efficient p-n heterojunction photocatalysts has stimulated great interest. Herein, we report the design and synthesis of fiber-shaped Ag 2 O/Ta 3 N 5 p-n heterojunctions as a kind of efficient photocatalysts. Ta 3 N 5 nanofibers were prepared by an electrospinning-calcination-nitridation method, and then the in-situ anchoring of Ag 2 O on their surfaces was realized by a facile deposition method. The resulting Ag 2 O/Ta 3 N 5 heterojunctions were comprised of porous Ta 3 N 5 nanofibers (diameter: ∼150nm) and Ag 2 O nanoparticles (size: ∼12nm). The photocatalytic activity of these heterojunctions were studied by decomposing rhodamine B (RhB) dye and tetracycline (TC) antibiotic under visible light (λ>400nm). In all the samples, the heterojunction with Ag 2 O/Ta 3 N 5 molar ratio of 0.2/1 displays the best activity. It is found that a synergistic effect contributes to the effective suppression of charges recombination between Ta 3 N 5 and Ag 2 O, leading to an enhanced photocatalytic activity with good stability. The photogenerated holes (h + ) and superoxide radicals (O 2 - ) play dominant roles in the photocatalytic process. These p-n heterojunctions will have great potential for environmental remediation because of the facile preparation process and exceptional photocatalytic activity., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Boron carbide/graphitic carbon nitride (B4C/g-C3N4) p-n hetero-junction photocatalyst with an internal electric field was synthesized by a facile solvent evaporation method and characterized by field emission scanning electron microscope (FESEM), UV-Vis diffuse reflectance spectra (UV-Vis DRS), photoluminescence spectra (PL), etc. Photocatalytic activity of the composite B4C/g-C3N4 loaded with Pt co-catalyst was evaluated using CO2 conversion to CH4 with H2 as the hydrogen source and reductant under visible light irradiation. The coupling of p-type B4C with n-type g-C3N4 significantly improved the performance of photocatalytic CO2 reduction; with the optimum B4C mass fraction of 1/6, the composite photocatalyst showed approximately 6 and 8 times higher CH4 generation rate than g-C3N4 and B4C, respectively. The enhancement was attributed to efficient photo-excited electron/hole separation due to the formation of internal electric field at the p-B4C/n-C3N4 interface., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Enhanced light absorption and effective separation of photogenerated charges are the main strategies to improve the performance of photocatalytic materials. In this study, Ag3PO4/N-doped BiPO4 (N-BiPO4) core-shell structure photocatalyst was synthesized by a simple in-situ growth strategy in an organic solvent. The separation of photogenerated electron-hole was enhanced by the doping of nitrogen, because of the emergence of N-O impurity energy levels. The increased photocatalytic activity of Ag3PO4/N-BiPO4 could be attributed to the in-situ formation of chemical bonds between Ag3PO4 and N-BiPO4, which accelerate the separation of electron-hole pairs. The photocatalytic performance of the as-synthesized Ag3PO4/N-BiPO4 was evaluated by monitoring the decolorization of methyl orange under sunlight irradiation. Ag3PO4/N-BiPO4 was capable of bleaching 95% MO within 40min., (Copyright © 2015 Elsevier Inc. All rights reserved.)