Superior solar-to-hydrogen energy conversion efficiency by visible light-driven hydrogen production via highly reduced Ti2+/Ti3+ states in a blue titanium dioxide photocatalyst

Silva, Nuwan L. De; Jayasundera, Anil C. A.; Folger, Alena; Kasian, Olga; Zhang, Siyuan; Yan, Changfeng; Scheu, Christina; Bandara, Jayasundera

doi:10.1039/c8cy01212a

Cited by 34 publications

(21 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The prepared suspension flask was placed under the visible light source (Solar Light-XPS 300 with cutoff filter λ ≥ 420 nm) to carry out PC-HER studies and stirred magnetically for homogeneity for 8 h. The evolution of hydrogen was hourly controlled by a Shimadzu GC2010Plus gas chromatograph, taken from the headspace of the reaction flask by a syringe. In addition, the solar-to-hydrogen (STH) efficiency of photocatalysts was calculated according to eq Herein, R H 2 , Δ G °, P , and A represent the amount of hydrogen, Gibbs free energy for generating 1 mol of hydrogen, sunlight intensity, and irradiation area, respectively.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Improving the Photocatalytic Hydrogen Generation Using Nonaggregated Zinc Phthalocyanines

Acar

Yüzer

Kurtay

et al. 2021

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

In comparison to traditional solar cells, the dye-sensitized photocatalytic system is one of the most appealing artificial photosynthesis mechanisms due to its low cost and straightforward fabrication. Herein, the photoelectrochemical and photocatalytic hydrogen evolution reactions of Zn-based phthalocyanine (Pc) derivatives, abbreviated as ZnPc-1 and ZnPc-2, were primarily studied in the presence of TEOA sacrificial electron donor. To this aim, the PC activities of ZnPc-1/TiO 2 and ZnPc-2/TiO 2 photocatalysts were investigated in the absence and presence of a cocatalyst. For the first hour, the amount of hydrogen generated by ZnPc derivatives (ZnPc-1/TiO 2 and ZnPc-2/TiO 2 ) was determined to be 1.221 and 0.864 mmol g −1 h −1 , respectively. Additionally, the solar-to-hydrogen conversion efficiencies of ZnPc-1/ TiO 2 and ZnPc-2/TiO 2 were ascertained to be 3.15% and 2.22%, respectively. Interestingly, STH efficiencies of photocatalysts were increased about 4-fold in the presence of a cocatalyst. Consequently, to elucidate the structural properties of ZnPc-1 and ZnPc-2, density functional theory (DFT) and time-dependent DFT studies were also conducted, and it was discovered that noncovalent interactions and steric hindrance effects on ZnPc-2 are tightly related to the experimentally determined PC activity differences between ZnPc-1 and ZnPc-2.

show abstract

Section: Methodsmentioning

confidence: 99%

“…In addition, the solar-to-hydrogen (STH) efficiency of photocatalysts was calculated according to eq 6. 55 R G PA STH 100…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Improving the Photocatalytic Hydrogen Generation Using Nonaggregated Zinc Phthalocyanines

Acar

Yüzer

Kurtay

et al. 2021

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

show abstract

“…Spectra collected from both d‐UV‐Ti x O y and d‐Ti x O y show two peaks of Ti L 2,3 edges without further splitting, characteristic for an amorphous structure [72] . Compared to the spectrum collected from d‐Ti x O y , the Ti L 2,3 edge for d‐UV‐Ti x O y shows a chemical shift of around 0.5 eV towards lower energy loss, suggesting the reduction of Ti 4+ species to Ti 3+ [73,74] . Even after exposing the samples to an oxygen‐rich atmosphere, traces of the reduced species remain.…”

Section: Resultsmentioning

confidence: 95%

“… [72] Compared to the spectrum collected from d‐Ti x O y , the Ti L 2,3 edge for d‐UV‐Ti x O y shows a chemical shift of around 0.5 eV towards lower energy loss, suggesting the reduction of Ti 4+ species to Ti 3+ . [ 73 , 74 ] Even after exposing the samples to an oxygen‐rich atmosphere, traces of the reduced species remain. Multivariate statistical analysis [75] of the EELS spectrum imaging (Figure S10) confirms that in the case of d‐UV‐Ti x O y the particles are overall more reduced.…”

Section: Resultsmentioning

confidence: 99%

Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase

Şahin

Dai

Chan

et al. 2021

Chemistry A European J

View full text Add to dashboard Cite

Amorphous TixOy with high surface area has attracted significant interest as photocatalyst with higher activity in ultraviolet (UV) light‐induced water splitting applications compared to commercial nanocrystalline TiO2. Under photocatalytic operation conditions, the structure of the molecular titanium alkoxide precursor rearranges upon hydrolysis and leads to higher connectivity of the structure‐building units. Structurally ordered domains with sizes smaller than 7 Å form larger aggregates. The experimental scattering data can be explained best with a structure model consisting of an anatase‐like core and a distorted shell. Upon exposure to UV light, the white TixOy suspension turns dark corresponding to the reduction of Ti4+ to Ti3+ as confirmed by electron energy loss spectroscopy (EELS). Heat‐induced crystallisation was followed by in situ temperature‐dependent total scattering experiments. First, ordering in the Ti−O environment takes place upon to 350 °C. Above this temperature, the distorted anatase core starts to grow but the structure obtained at 400 °C is still not fully ordered.

show abstract

“…A relatively weak Ti 2p peak was detected for Ni 0.5 Pt 0.5 /meso-TiO 2 divided into two peaks at binding energy of 458.48 eV (Ti 2p 3/2 ) and 464.16 (Ti 2p 1/2 ), confirming the presence of Ti 4 + ions of rutile TiO 2 phase. [48,49] The typical peaks of Ti at 458.68 and 458.48 eV belong to Ti 2p 3/2 for meso-TiO 2 and Ni 0.5 Pt 0.5 /m-TiO 2 , suggesting that the oxidation state of Ti decreased with metal NiPt added. Compared with that of meso-TiO 2 , it is worth noting that the binding energy of C 1s and O 1s band for Ni 0.5 Pt 0.5 /m-TiO 2 displays an positive and negative shift, respectively, (Figure 4b, c), may be attributed to the interaction with Ni/Pt.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

Achieving Complete Hydrogen Evolution from N2H4BH3 over Mesoporous TiO2 Immobilized NiPt Alloy Nanoparticles

Liu

Wan

et al. 2021

ChemistrySelect

View full text Add to dashboard Cite

Mesoporous materials, as the supports in the fabrication of catalyst, are beneficial for the dispersion of the metal active sites in the pores. Herein, highly dispersed NiÀ Pt alloy nanoparticles deposited on mesoporous TiO 2 was facilely and successfully fabricated via a one-step reduction method towards hydrogen generation from N 2 H 4 BH 3 . Unexpectedly, the optimized Ni 0.5 Pt 0.5 /meso-TiO 2 exhibits superior catalytic prop-erty and 100 % selectivity with a turnover frequency (TOF) value of 77.06 min À 1 in the existence of sodium hydroxide at 323 K. Meanwhile, the catalyst achieves high stability and reusability even after five recycles. This study provides one new way for preparation of mesoporous TiO 2 supported metal NPs for hydrogen generation reaction [a

show abstract

Superior solar-to-hydrogen energy conversion efficiency by visible light-driven hydrogen production via highly reduced Ti²⁺/Ti³⁺ states in a blue titanium dioxide photocatalyst

Abstract: A catalytic hydrogen production system was developed with TiO2 that contains Ti3+/Ti2+ reduced states which act as both visible and IR light harvesting components as well as the catalytic site.

Cited by 34 publications

References 60 publications

Improving the Photocatalytic Hydrogen Generation Using Nonaggregated Zinc Phthalocyanines

Improving the Photocatalytic Hydrogen Generation Using Nonaggregated Zinc Phthalocyanines

Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase

Achieving Complete Hydrogen Evolution from N2H4BH3 over Mesoporous TiO2 Immobilized NiPt Alloy Nanoparticles

Contact Info

Product

Resources

About