Visible-light-active g-C 3 N 4 /N-doped Sr 2 Nb 2 O 7 heterojunctions as photocatalysts for the hydrogen evolution reaction
Visible light active photocatalytic performance of g-C 3 N 4 /NSON-X heterojunctions.
14 SOLAR ENERGY↗
Engineering topics
Chen, Vincent W.
Publications and source records attributed to Chen, Vincent W..
Enhanced visible light photocatalytic water reduction from a g-C 3 N 4 /SrTa 2 O 6 heterojunction
In this paper, a new g-C 3 N 4 /SrTa 2 O 6 heterojunction photocatalyst was designed and prepared by chimie douce (soft chemistry) method where carbon nitride (g-C 3 N 4 ) was deposited over the metastable perovskite phase of SrTa 2 O 6 . The morphological study of the heterojunction using SEM and STEM revealed that g-C 3 N 4 nanofibers are dispersed uniformly on the surface of SrTa 2 O 6 plates leading to the intimate contact between them. The heterojunction could achieve a high and stable visible light photocatalytic H 2 generation of 137 mmol/h/mole of g-C 3 N 4 , which is much larger than the amount of hydrogen generated by one mole of pristine g-C 3 N 4 . Finally, a plausible mechanism for the observed enhanced photocatalytic activity for the heterojunction is proposed on the basis of effective charge separation of photogenerated electron-hole pairs, supported by band position calculations and photo-physical properties of g-C 3 N 4 and SrTa 2 O 6 .
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
A Visible-Light-Active Heterojunction with Enhanced Photocatalytic Hydrogen Generation
A visible-light-active carbon nitride (CN)/strontium pyroniobate (SNO) heterojunction photocatalyst was fabricated by deposition of CN over hydrothermally synthesized SNO nanoplates by a simple thermal decomposition process. The microscopic study revealed that nanosheets of CN were anchored to the surface of SNO resulting in an intimate contact between the two semiconductors. Diffuse reflectance UV/Vis spectra show that the resulting CN/SNO heterojunction possesses intense absorption in the visible region. The structural and spectral properties endowed the CN/SNO heterojunction with remarkably enhanced photocatalytic activity. Specifically, the photocatalytic hydrogen evolution rate per mole of CN was found to be 11 times higher for the CN/SNO composite compared to pristine CN. The results clearly show that the composite photocatalyst not only extends the light absorption range of SNO but also restricts photogenerated charge-carrier recombination, resulting in significant enhancement in photocatalytic activity compared to pristine CN. The relative band positions of the composite allow the photogenerated electrons in the conduction band of CN to migrate to that of SNO. This kind of charge migration and separation leads to the reduction in the overall recombination rate of photogenerated charge carriers, which is regarded as one of the key factors for the enhanced activity. In conclusion, a plausible mechanism for the enhanced photocatalytic activity of the heterostructured composite is proposed based on observed activity, photoluminescence, time-resolved fluorescence emission decay, electrochemical impedance spectroscopy, and band position calculations.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
ControlShell: A real-time software framework
The ControlShell system is a programming environment that enables the development and implementation of complex real-time software. It includes many building tools for complex systems, such as a graphical finite state machine (FSM) tool to provide strategic control. ControlShell has a component-based design, providing interface definitions and mechanisms for building real-time code modules along with providing basic data management. Some of the system-building tools incorporated in ControlShell are a graphical data flow editor, a component data requirement editor, and a state-machine editor. It also includes a distributed data flow package, an execution configuration manager, a matrix package, and an object database and dynamic binding facility. This paper presents an overview of ControlShell's architecture and examines the functions of several of its tools.
Schneider, Stanley A.↗
ControlShell - A real-time software framework
ControlShell is designed to enable modular design and impplementation of real-time software. It is an object-oriented tool-set for real-time software system programming. It provides a series of execution and data interchange mechansims that form a framework for building real-time applications. These mechanisms allow a component-based approach to real-time software generation and mangement. By defining a set of interface specifications for intermodule interaction, ControlShell provides a common platform that is the basis for real-time code development and exchange.
Schneider, Stanley A.↗