Recent advances for dyes removal using novel adsorbents: A review

Hydrogen (H2) production via photocatalytic water splitting is one of the most promising technologies for clean solar energy conversion to emerge in recent decades. The achievement of energy production from water splitting would mean that we could use water as a fuel for future energy need. Among the various photocatalytic materials, titanium dioxide (TiO2) is the dominant and most widely studied because of its exceptional physico-chemical characteristics. Surface decoration of metal/non-metal on TiO2 nanoparticles is an outstanding technique to revamp its electronic properties and enrich the H2 production efficiency. Metal dopants play a vital role in separation of electron-hole pairs on the TiO2 surface during UV/visible/simulated solar light irradiation. In this paper, the basic principles, photocatalytic-reactor design, kinetics, key findings, and the mechanism of metal-doped TiO2 are comprehensively reviewed. We found that Langmuir-Hinshelwood kinetic model is commonly employed by the researchers to demonstrate the rate of H2 production. Copper (Cu), gold (Au) and platinum (Pt) are the most widely studied dopants for TiO2, owing to their superior work function. The metal dopants can amplify the H2 production efficiency of TiO2 through Schottky barrier formation, surface plasmon resonance (SPR), generation of gap states by interaction with TiO2 VB states. The recent advances and important consequences of 2D materials, perovskites, and other novel photocatalysts for H2 generation have also been reviewed.

Photocatalytic hydrogen production using metal doped TiO2: A review of recent advances

Production of bricks from waste materials – A review

A critical review in strategies to improve photocatalytic water splitting towards hydrogen production

In this work, an in-situ Fe-doped g-C3N4 catalyst was synthesized by thermal shrinkage polymerization. A heterogeneous photocatalysis-Fenton system was formed with the addition of H2O2 under visible irradiation and exhibited excellent and recyclable removal performance for refractory contaminants such as: phenol, bisphenol A, 2, 4-dichlorophenol and coking wastewater, which was due to the formation of σ-π bonds via Fe and N element in the triazine ring skeleton of Fe-g-C3N4. The electrons generated can be quickly transferred to Fe3+ to form Fe2+ under the interaction of the chemical bond. The efficiency of photoelectron separation was accelerated, and OH radicals were quickly generated with the reaction between Fe2+ and H2O2. Specifically, the recycling of Fe can be achieved in the heterogeneous system, which avoids the problems for the recycling and secondary pollution of Fe ions in homogeneous Fenton reaction. Parameters such as Fe doping amount, hydrogen peroxide concentration, pH value, catalyst concentration, and complex wastewater (coking wastewater) were optimized. The degradation of coking wastewater were also performed, and the chemical oxygen demand (COD) and total organic carbon (TOC) values for 300 ml coking wastewater could be reduced from 64.6 and 25.3 mg/L to 22.8 and 12.3 mg/L in 60 min, respectively. These results demonstrate photocatalysis-Fenton reaction with Fe-g-C3N4 catalyst is promising for environmental remediation.

In-situ Fe-doped g-C3N4 heterogeneous catalyst via photocatalysis-Fenton reaction with enriched photocatalytic performance for removal of complex wastewater

Improving the photocatalytic property of g-C3N4 by combined strategies has attracted increasing attention recently. In this work, we realized the structure nanosizing of g-C3N4 and its synchronous compounding with TiO2 nanoparticles in one step, using a facile melamine-involved vapor deposition method coupled with a simple and easy setup. Nanostructured g-C3N4/TiO2 heterojunction was well-established and the resultant nanocomposite demonstrated an excellent visible-light photocatalytic H2 evolution performance 10.8 times higher than that of bulk g-C3N4. The structure nanosizing coupled with the heterojunction construction contributed together to the improvement of photoinduced electron-hole separation and final photocatalytic efficiency. The proposed simple method and setup have the potential to be used for preparing other g-C3N4-based nanocomposites with advanced photocatalytic properties.

Jun Zhou

Papers

One-step synthesis of nanostructured g-C3N4/TiO2 composite for highly enhanced visible-light photocatalytic H2 evolution

Utilization of waste phosphogypsum to prepare non-fired bricks by a novel Hydration–Recrystallization process

Effects of pH dynamics on solidification/stabilization of municipal solid waste incineration fly ash.

Facile preparation of hollow-nanosphere based mesoporous g-C3N4 for highly enhanced visible-light-driven photocatalytic hydrogen evolution

A green one-pot approach for mesoporous g-C3N4 nanosheets with in situ sodium doping for enhanced photocatalytic hydrogen evolution