J. Appl. Cryst.の発刊に際して

2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519

Semiconductor-based Photocatalytic Hydrogen Generation

Photoelectrochemical (PEC) cells offer the ability to convert electromagnetic energy from our largest renewable source, the Sun, to stored chemical energy through the splitting of water into molecular oxygen and hydrogen. Hematite (α-Fe(2)O(3)) has emerged as a promising photo-electrode material due to its significant light absorption, chemical stability in aqueous environments, and ample abundance. However, its performance as a water-oxidizing photoanode has been crucially limited by poor optoelectronic properties that lead to both low light harvesting efficiencies and a large requisite overpotential for photoassisted water oxidation. Recently, the application of nanostructuring techniques and advanced interfacial engineering has afforded landmark improvements in the performance of hematite photoanodes. In this review, new insights into the basic material properties, the attractive aspects, and the challenges in using hematite for photoelectrochemical (PEC) water splitting are first examined. Next, recent progress enhancing the photocurrent by precise morphology control and reducing the overpotential with surface treatments are critically detailed and compared. The latest efforts using advanced characterization techniques, particularly electrochemical impedance spectroscopy, are finally presented. These methods help to define the obstacles that remain to be surmounted in order to fully exploit the potential of this promising material for solar energy conversion.

Solar Water Splitting: Progress Using Hematite (α‐Fe2O3) Photoelectrodes

Energy harvesting generators are attractive as inexhaustible replacements for batteries in low-power wireless electronic devices and have received increasing research interest in recent years. Ambient motion is one of the main sources of energy for harvesting, and a wide range of motion-powered energy harvesters have been proposed or demonstrated, particularly at the microscale. This paper reviews the principles and state-of-art in motion-driven miniature energy harvesters and discusses trends, suitable applications, and possible future developments.

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Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices

Review of the proton exchange membranes for fuel cell applications

Pencirian fizikal dan terma komposit seramik elektrolit SDC-(Li/Na) 2CO 3

Fabrication of Carbon Doped TiO2 Nanotubes via In-situ Anodization of Ti-foil in Acidic Medium

Organic catalyst has recently been identified as the potential substitution for expensive platinum electrocatalyst for fuel cell application. Numerous studies have shown that the nitrogen-containing carbon nanotubes (N-CNT) can be synthesized through spray pyrolysis or floating chemical vapor deposition (CVD) technique using various type of organometallic as precursors. This paper presents the method of synthesis and the initial findings of the growth of N-CNT directly on carbon paper using a modified CVD technique. In this research, nickel (II) phthalocyanines (Ni-Pc) as precursor was dissolved in ethanol solvent, stirred and sonicated to become homogenized. The solution was poured into a bubbler and heated up to allow the mixture to vaporize. Subsequently, the solution vapor was flowed into the tubical reactor maintained at 900°C. Carbon paper sputtered with nickel nanoparticles was used as the substrate. The synthesized sample was examined through Field Emission Scanning Electron Microscopy (FESEM), At...

Direct synthesis of nitrogen-containing carbon nanotubes on carbon paper for fuel cell electrode

The main objective of this paper is to develop a PEMFC for mobile and portable application using methanol as the fuel sources. From the economic view of point, this design is very competitive with conventional internal combustion engine, ICE. The advantage of fuel cell usage is able to reduce the environmental pollution as well as the world demand of fossil fuels. The electricity cost was calculated as RM 0.16kWh -1 compared to the current existing cost of TNB as RM 0.218kWh -1

Clean cheap and compact (3c) power generation system for mobile and portable application: pem fuel cell

Although ultrafiltration has replaced many liquid phase separation equipment, it is still considered as a “non‐unit operation” process because the sizing of the equipment could not be calculated using either the equilibrium stage or the rate‐based methods. Previous design methods using the dead‐end and the complete‐mixing models are unsatisfactory because the dead‐end model tends to underestimate the membrane area due to the use of the feed concentration in the driving force while the complete‐mixing model tends to overestimate the membrane area due to the use of the more concentrated rejection concentration in the driving force. In this paper, a cross‐flow model for ultrafiltration is developed by considering mass balance at a differential element of the cross‐flow module and then integrating the expression over the whole module to get the module length. Since the modeling is rate‐based, the length of both modules could be expressed as the product of the height of a transfer unit (HTU) and the n...

Wan Ramli Wan Daud

Papers

Pencirian fizikal dan terma komposit seramik elektrolit SDC-(Li/Na) 2CO 3

Fabrication of Carbon Doped TiO2 Nanotubes via In-situ Anodization of Ti-foil in Acidic Medium

Direct synthesis of nitrogen-containing carbon nanotubes on carbon paper for fuel cell electrode

Clean cheap and compact (3c) power generation system for mobile and portable application: pem fuel cell

Rate‐Based Design of Non‐fouled Cross‐Flow Hollow Fiber Membrane Modules for Ultrafiltration