On the Optical Properties of Ag+15 Ion-beam-irradiated TiO2 and SnO2 Thin Films

Hardeep Thakur,K. K. Sharma,Ravi Kumar,Pardeep Thakur,Yogesh Kumar,Abhinav Pratap Singh,Sanjeev Gautam,채근화 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.10

The effects of 200 MeV Ag⁺¹⁵ ion irradiation on the optical properties of TiO₂ and SnO₂ thin films prepared by RF magnetron sputtering technique were investigated. These films were characterized by the UV-vis spectroscopy and it was observed that with increase in irradiation fluence the transmittance for the TiO₂ films systematically increases while that for SnO₂ decreases. Absorption spectra of the irradiated samples showed a minor changes in indirect bandgap from 3.44 to 3.59 eV for TiO₂ while that for SnO₂ significant modifications in the direct bandgap from 3.92 to 3.6 eV were observed on increasing irradiation fluence. The observed modifications in the optical properties of both TiO₂ and SnO₂ systems with irradiation can be attributed to controlled structural disorder/defects in the system.

Advanced strategies for modifying the water splitting performance of MoSe2 photocatalyst: A critical review of recent progress

Vaishnavi Sharma,Abhinandan Kumar,Pardeep Singh,Praveen Kumar Verma,Tansir Ahamad,Sourbh Thakur,Quyet Van Le,Van Huy Nguyen,Aftab Aslam Parwaz Khan,Pankaj Raizada 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Water splitting technology is rapidly evolving in order to generate H2 in a sustainable manner to amendthe global energy crisis. Water splitting over semiconductor catalyst nanoparticles for large-scale hydrogenproduction has shown to be a simple and affordable procedure, attracting researchers from aroundthe world for more fruitful studies and development in the field of photocatalysis. In this respect,MoSe2 is a promising semiconductor photocatalyst owing to its non-toxic nature, low Gibbs free energy,high metallic character, impressive opto-electronic properties, and outstanding photocatalytic performance. Moreover, the 2D nature of MoSe2 allows the easy tuning of the bandgap to suit H2 evolution reactionapplication by simple synthesis techniques. Therefore, in this review, we have comprehensivelydiscussed the influence of morphology on photocatalytic water splitting with a main focus on the nanostructuremodifications to modulate the properties of MoSe2. In detail, starting from the crystal structureand optimal photocatalytic features of MoSe2, insights into photocatalytic water splitting have been highlighted. Various modes of nanostructure designs involving hydro(solvo)thermal, CVD, PVD, exfoliation,and intercalation are outlined. The lower bandgap energy is subjected to a high rate of photoinducedexcitons recombination, which reduces its photocatalytic efficiency. Therefore, modification techniquessuch as doping, heterostructure construction, and vacancy generation are presented in order to concurrentlyimprove the photocatalytic water splitting performance. Finally, the study concludes with a summaryof recent advancements and anticipated potential trends in this area to instigate further researchendeavours.

An overview of converting reductive photocatalyst into all solid-state and direct Z-scheme system for water splitting and CO2 reduction

Pankaj Raizada,Abhinandan Kumar,Vasudha Hasija,Pardeep Singh,Vijay Kumar Thakur,Aftab Aslam Parwaz Khan 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.93 No.-

Considering the current scenario of rising environmental and energy concerns, engineering of Z-schemephotocatalytic systems is in the spotlight. The prime reason for this includes efficient redox abilities andeffective space separation along with the migration of photoinduced charge carriers over conventionalheterojunction systems. Herein we foreground the stumbling blocks of traditional heterojunctionsystems and enlighten the generations of Z-scheme photocatalysis originating from liquid-phase todirect Z-scheme photocatalytic systems. We provide substantial criteria and selection aspects ofchoosing reductive type photocatalysts as a potential aspirant for the Z-scheme photocatalytic system. AsZ-scheme photocatalytic systems render effective space separation of photogenerated carriers, activespecies generation, wide optical absorption and amended redox ability. We focus on comprehensiveillustration of all solid-state and direct Z-scheme photocatalysts by coupling reductive typephotocatalysts with other semiconductor material and explored their potential for efficacious conversionof solar energy into functional energy. Herein, we aim to provide in-depth and updated criteria forselecting Z-scheme photocatalysts for CO2 reduction, water splitting, and nitrogenfixation. Lastly, thearticle compiles with a conclusive note about future perspectives and challenges accompanying all solidstateand direct Z-scheme Z photocatalysts and their energy conversion applications.

BiFeO3-based Z scheme photocatalytic systems: Advances, mechanism, and applications

Aastha Dhawan,Anita Sudhaik,Pankaj Raizada,Sourbh Thakur,Tansir Ahamad,Pankaj Thakur,Pardeep Singh,Chaudhery Mustansar Hussain 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

Hitherto, heed has been paid substantially to concoct potential photocatalysts to counter the issues ofenvironmental degradation and energy crises. Amongst the plethora of photocatalysts, BiFeO3 (BFO)based photocatalysts are blooming as a centre of attraction due to fine chemical stability, and easy extraction. Also owing to a 2.2–2.8 electron volt (eV) narrow bandgap, BFO to has turned into a competent photocatalystfor efficient visible light absorption. So, keeping in mind the advantages of BFO and reviewingprevious reports, the present review offers a deep overview of conventional heterojunctions andadvanced Z-scheme heterojunctions. The main focus of the review is on BFO-based Z-scheme heterojunctionsalong with photocatalytic mechanisms and various applications. The successful construction ofBFO-based Z-scheme heterojunction eliminates drawbacks of bare BFO photocatalysts such as shortlivedcharge carriers, and high recombination rate, and also enhances light absorption of the system asa whole. Because of spatially separated oxidation and reduction sites and efficacious charge migration,BFO-based Z-scheme heterojunctions are proficient contenders among photocatalytic materials. Therefore, BFO-based Z-scheme heterojunctions are aptly used nowadays, in various fields like pollutantdegradation, wastewater treatment, organic synthesis, hydrogen production, and treatment ofantibiotics.

Recent advances in enhanced photocatalytic activity of bismuth oxyhalides for efficient photocatalysis of organic pollutants in water: A review

Kirti Sharma,Vishal Dutta,Sheetal Sharma,Pankaj Raizada,Ahmad Hosseini-Bandegharaei,Pankaj Thakur,Pardeep Singh 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.78 No.-

Recently, layered bismuth oxyhalides (BiOX, X = F, Cl, Br and I) have received significant attention aspotential photocatalysts for energy and environment applications. However, limited visible light activityand recombination of photogenerated charge carriers limit their applications for photocatalytic waterpurification. In this review, various strategies such as heterojunction formation, metal/non-metal doping,interface modification, enhancement in Bi content, inner coupling between different BiOX photocatalyst,use of sensitizers and creation of oxygen vacancies was deliberated for improved photocatalyticperformance of BiOX. The integration of BiOX with other photocatalysts, mechanism for enhancedactivity and conclusive outlook with future challenges was also elaborated.

Current status on designing of dual Z-scheme photocatalysts for energy and environmental applications

Rohit Kumar,Anita Sudhaik,Aftab Aslam Parwaz Khan,Pankaj Raizada,Abdullah M. Asiri,Satyabrata Mohapatra,Sourbh Thakur,Vijay Kumar Thakur,Pardeep Singh 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.106 No.-

Growing pollution and high energy demand are some of the major issues against humans. Waterpollution is one of the main problems created due to industrial waste and irresponsible human activities. Nowadays, photocatalysis is rising as an efficient alternative to overcome the energy requirement andwater purification, as it can use solar light as a source of energy. Due to some limitations of photocatalysts,such as photocarriers recombination, low surface area, and limited light absorption, modificationssuch as defect modifications, heterojunction can be employed. Out of all, Z-scheme heterojunction is aproficient way to overwhelm the limitation of pristine photocatalysts. To enhance the activity of Zschemephotocatalyst, even more, a dual Z-scheme photocatalytic scheme has been developed in whichtwo Z-scheme based charge transfer occur simultaneously on a ternary photocatalyst. In this review, wehave discussed the different types of dual Z-schemes along with their application in water purificationand finally, we have discussed the future prospects for further research.