Self-assembly of three-dimensional CdS nanosphere/graphene networks for efficient photocatalytic hydrogen evolution

In this work, we report the construction of three-dimensional(3D) CdS nanosphere/graphene networks by a one-step hydrothermal self-assembly route. The 3D graphene networks not only enhance the light scattering, thanks to the interconnected 3D architecture, but also improve the crystallinity of deposited CdS nanospheres, and at the same time provide a direct electron pathway to quickly separate the photogenerated electron-hole pairs from CdS, which thus dramatically improve the photocatalytic activity.The optimized 3D CdS nanosphere/graphene networks with 2 wt% of graphene could produce molecular hydrogen at a rate of 2310 μmol gcatalyst^(-1) h^(-1) under visible-light illumination(λ > 400 nm).

Making fully printed perovskite solar cells stable outdoor with inorganic superhydrophobic coating

Outdoor environment including moisture, dust, UV, oxygen and thermal stress(repeated heating-cooling)is devastating to perovskite solar cells(PSCs). Here, we demonstrate a new strategy to make fully printed PSCs stable with maximum power output in outdoor environment by coating them with a porous hydrophobic inorganic layer. After coating, the PSCs can maintain superior stability of more than 150 days of outdoor storage, 240 h of continuous operation at the maximum power output point in ambient air with relative humidity as high as ~80%, and stable operation for more than 10 h under raining condition. ANSYS simulation shows that the thin and porous nature of the inorganic coating layer offers much better heat dissipation than conventional encapsulation methods using glasses attached by photocurable epoxy. A similar thermal expansion coefficient of the inorganic encapsulation material with the solar cell substrate can also prevent it from cracking after repeated heating-cooling cycles. All of these merits resulted from our encapsulation method endow the perovskite solar cells with the real outdoor working capability.

Reconfiguration Cost Analysis Based on PetriNet for Manufacturing System

Nowadays, manufacturers are faced with severe challenges to response rapidly to changing demands and meet various customers’ needs with respect to production volume and product profile. Reconfigurable manufacturing paradigm was proposed as an advanced manufacturing philosophy to enhance the adaptability and flexibility of manufacturing sys-tems. By physical and logical reconfiguration, Reconfigurable Manufacturing System (RMS) is able to fulfil customers’ needs in a cost-effective way by making full use of the resources currently available. This paper focuses on studying of reconfiguration cost of such systems. In this paper, DEDS modelling method Petri Net is used to construct the model for reconfiguration process of RMS which includes physical reconfiguration cost factors and conjunction matrix is used to describe the production processes. By highlighting the differences in the process set before and after reconfiguration, the reconfiguration principles have been proposed to describe and guide the process of the manufacturing system re-configuration. The simulation example is given to prove the validation of the proposed model.

Sustainable hydrogen and chemical production via photo-electrochemical reforming of biomass-derived alcohols

Hydrogen production from steam or autothermal alcohol reforming has been widely studied, but these methods require high temperatures and emit CO2. Here, we present a new strategy for the simultaneous room-temperature production of hydrogen and other chemicals without the emission of CO2, via the photo- electrochemical reforming of biomass-derived alcohols. The measured hydrogen quantum efficiencies reach around 80% across the entire visible solar spectrum from 450 to 850 nm, achieving an ultrahigh hydrogen production rate of 7.91 μmol/（min·cm^2） under AM 1.5G illumination.

Two 2D uranyl coordination complexes showing effective photocatalytic degradation of Rhodamine B and mechanism study

Two new hydrostable two-dimensional(2 D) uranyl coordination complexes [(UO_(2))_(5)(μ_(3)-O)_(2)(nbca)_(2)].7 H_(2)O(1) and [(UO_(2))_(3)(nbca)_(2)(H_(2)O)_(3)]·2 H_(2)O(2)(H_(3) nbca=5-nitro-1,2,3-benzenetricarboxylic acid) were hydrothermal synthesized.Single-crystal structural refinements reveal that both of the two complexes were formed by the packing of 2D uranyl coordination sheets via the hydrogen bonds.The nbca ligand coordinating to the uranyl polyhedron centers constructed the 2D sheets.There are UO8 hexagonal bipyramids and UO7 pentagonal bipyramids in 1 while only U07 pentagonal bipyramids in 2.Photocatalytic degradation of rhodamine B(RhB) in aqueous solution was studied.Complex 2 possesses better performance than 1 with 96.2 % of the RhB was degraded in only 60 min.Mechanism studies reveal that the dissolved oxygens are essential to the RhB degradation.The photocurrent density of 2 is more stable than that of 1,which indicating the stronger ability to separate photoexcited electrons and hole pairs of 2.

Service outsourcing strategy decision for value creation in manufacturing firms

This study aims to resolve the difficult problem of manufacturers’service outsourcing strategy decision-making,with services divided into two types:hygienic and motivational.We build a value creation model for the manufacturer,service contractor,and customer under different outsourcing strategies,and we examine optimal outsourcing decision-making in various scenarios and its effect on the value creation of related entities.The results indicate that motivational services have a lower bound characterized by service utility.When the manufacturer derives services higher than this lower bound,it should operate its own motivational service and outsource the hygienic service to create greater value.When the manufacturer is limited by resources or capabilities and is required to outsource the motivational service,it can maintain value creation by setting an appropriate contract coefficient.The service contractor should undertake motivational services within the contract boundary negotiated by the manufacturer and conduct hygienic services outside the boundary.Theoretically,outsourcing both service types can maximize customer value,but this may not achieve the manufacturers’optimal value creation.