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[Display omitted] • An integrated method was used to recover copper from electroplating sludge. • 96.4% of Cu2+ was removed, and more than 57.3% of Cu2+ was recovered. • Electroplating sludge compartments provided high current efficiency/energy saving. • No acid or alkali was added to the electroplating sludge during the whole process. • No wastewater was discharged during the whole treatment process. Electroplating sludge, though a hazardous waste, is a valuable resource as it contains a large amount of precious metals. In this study, copper was recovered from the electroplating sludge using a technology that integrates bipolar membrane electrodialysis (BMED) and electrodeposition. The experimental results showed that Cu2+ in the electroplating sludge was successfully separated and concentrated in the BMED system without adding any chemical reagents; the concentrated Cu2+ was recovered in the form of copper foil in an electrodeposition system. Current density clearly affected the Cu2+ separation and concentration in the BMED system; the current density, solution pH and Cu2+ concentration drastically affected the Cu2+ electrodeposition ratio and the morphology and purity of the obtained copper foil. Under the optimised experimental conditions, 96.4% of Cu2+ was removed from the electroplating sludge and 65.4% of Cu2+ was recovered in the foil form. On increasing the number of electroplating sludge compartments from one to two and three, the current efficiency for recovering Cu2+ increased from 17.4% to 28.5% and 35.2%, respectively, and the specific energy consumption decreased from 11.3 to 6.7 and 5.3 kW h/kg of copper, respectively. The purity of the copper foil was higher than 99.5%. Thus, the integrated technology can be regarded as an effective method for recovering copper from electroplating sludge. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid heterojunction solar cells have gained extensive attention due to the simple device structure and low‐cost technological processes, and n‐type silicon has been mainly used as the inorganic absorber in previous research. Herein, hybrid heterojunction solar cells based on p‐type silicon are successfully prepared through a low‐temperature solution method. A preliminary power conversion efficiency over 4% is observed, via optimizing the organic thin‐film deposition and organic/inorganic interface, which enhance the built‐in field and promote the separation of photogenerated carriers in the heterojunction. Therefore, a new idea and possibility are provided for developing low‐cost, high‐performance solar cells. [ABSTRACT FROM AUTHOR]

The performance of organic‐inorganic hybrid solar cells (HSCs) can be improved by modifying the hole transport layer (HTL). Poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is the most active HTL material in organic‐inorganic HSCs and has been widely studied. Nevertheless, charge transfer in PEDOT:PSS is limited and inefficient due to the presence of the weak ionic conductor PSS. Moreover, the working function of the PEDOT:PSS film and the passivation of the PSS at the Si/PEDOT:PSS interface play a crucial role in carrier separation. The focus of this work is to explore a universal modification method to simultaneously achieve improved charge transport and interfacial passivation capability when using PEDOT:PSS as HTL. By combining bilayer design and simple solution posttreatment, the direct current conductivity (σdc) and work function of the HTL based on PEDOT:PSS are increased to 765 S cm−1 and 5.00 eV, respectively. The organic‐inorganic HSCs prepared using this approach achieve a photovoltaic conversion efficiency (PCE) of 12.33%, achieving a 16.54% improvement over untreated devices. [ABSTRACT FROM AUTHOR]

With the introduction of the concept of dopant‐free carrier‐selective contact for c‐Si photovoltaics, Si‐based heterojunction solar cells can greatly reduce production costs by optimizing the manufacturing process while maintaining high power conversion efficiency. Compared with processes that rely on complex vacuum equipment, low‐temperature solution processing has many advantages over conventional silicon solar cells. However, research on low‐cost and high‐efficiency solar cells based on p‐type crystalline silicon is relatively rare. From the point of view regards energy band matching, the inorganic metal oxide semiconductor material ZnO is well suited for low‐cost solution method studies due to its easy preparation, very high transmittance in the visible spectrum, low cost, and suitable energy levels matching p‐Si. Herein, ZnO is spin coated on the back of p‐Si to form a heterojunction, together with spin coating of PEDOT:PSS on the front side as the hole transport layer and passivation layer, a PEDOT:PSS/p‐Si/ZnO‐structured p‐Si‐based backcontact hybrid solar cell is successfully fabricated at low temperature (≤135 °C) via solution process with a PCE of 9.77% (Voc = 0.56 V, Jsc = 25.99 mA cm−2, fill factor = 67.10%). This work provides a promising approach for fabricating high‐performance and low‐cost silicon‐based heterojunction solar cells. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide nanosheets@hollow nitrogen-doped carbon (MoS 2 @NC) spheres were prepared via a facile synthesis and investigated as a host material for ion storages. When used in lithium ion batteries (LIBs) or sodium ion batteries (SIBs), the MoS 2 @NC spheres electrodes exhibited excellent electrochemical performances. A high capacity of 1386 mAh g −1 after 100 cycles was obtained at a current density of 200 mA g −1 for LIBs. As for SIBs, a capacity of 330 mAh g −1 was retained after 400 cycles at 1000 mA g −1 . The remarkable ion storage performances can be attributed to the hierarchical architecture of the MoS 2 @NC spheres, which not only supply abundant active sites and efficient electron and ion pathways, but also alleviate the volume change of the active MoS 2 material. Meanwhile, synergistic effect of the heterogeneous components, interfacial ion storages, nitrogen doping and induced defects are responsible for high capacities of the MoS 2 @NC electrodes. And the electrodes exhibited enhanced electrochemical kinetics due to the significantly improved electrical conductivity and the large specific area of the MoS 2 @NC spheres. [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li-S) batteries have attracted extensive interest due to their higher theoretical energy density than the current commercial lithium-ion batteries. However, their practical application is largely hindered by the low sulfur utilization and poor cycling stability. Restraining the shuttle effect and enhancing the electrochemical kinetics are important for developing high-performance Li-S batteries. Here we use carbon nanofibers (CNFs) supported manganese dioxide (MnO 2 ) composite as a bifunctional coating on sulfur cathode for anchoring polysulfides and accelerating their redox reactions simultaneously. The CNFs/MnO 2 composite supplies fast paths for electron transfer and ion diffusion, and greatly promotes the transformation processes of polysulfides to Li 2 S/Li 2 S 2 , leading to an enhanced electrochemical kinetics. The diffusion coefficient of lithium ion has been increased by 560%. As a result, the CNFs/MnO 2 composite covered electrode exhibits an excellent cycling stability, its specific capacity maintains at about 600 mAh g −1 at 1C after 400 cycles, corresponding to a capacity decay as low as 0.063% per cycle, and the average coulombic efficiency reaches up to 99.66%. [ABSTRACT FROM AUTHOR]

The rock-salt structural manganous sulfide (α-MnS) is of higher lithium storage capacity. To improve the cyclability of α-MnS anode in lithium-ion batteries, we prepared a composite of α-MnS nanocrystallites grown on nitrogen and sulfur co-doped reduced graphene oxide (rGO) honeycomb framework. N and S atoms have been co-doped into rGO along with the growth of the α-MnS nanocystallites by a one-pot hydrothermal synthesis using thiourea as dopant and reactant. The typical α-MnS/N S co-doped rGO (NSG) composite electrode exhibits a reversible capacity as high as 763.5 mAh g −1 after 100 cycles at 100 mA g −1 , and a reversible capacity of 576.7 mAh g −1 even after 2000 cycles at 1000 mA g −1 . More importantly, the α-MnS/NSG composite electrodes show superior cycle performance at asymmetric discharge/charge current densities. The excellent electrochemical performance can be attributed to that the α-MnS nanocrystallites shorten lithium ion transmission distance, N-S co-doping improves the electronic conductivity of rGO, and the formation of chemical bonds combination between α-MnS and NSG enhances the electrode structural stability and the electron transport. In addition, more stable architecture of NSG-supported ultrafine α-MnS particles is formed upon cycling, which greatly enhances the electrical contact and further improves the electrochemical performance. [ABSTRACT FROM AUTHOR]