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CN-121988388-A - Preparation and application of double-photosensitizer-loaded dye-sensitized composite catalyst

CN121988388ACN 121988388 ACN121988388 ACN 121988388ACN-121988388-A

Abstract

A preparation and application of a double-photosensitizer loaded dye-sensitized composite catalyst belong to the fields of photocatalytic materials and new energy sources. The catalyst takes titanium dioxide as a carrier, platinum promoter is loaded on the surface of the catalyst, and a double photosensitizer system is formed by co-adsorbing micromolecular dye 2FMPA-BT-BA and an organic semiconductor receptor Y6 or IT 4F. Wherein, 2FMPA-BT-BA has strong absorption at 400-550 nm, Y6 or IT4F has strong absorption at 550-800 nm, and the two have complementary spectra, which synergistically widens the light response range to 400-800 nm. The platinum promoter can efficiently capture and transfer electrons and accelerate the kinetics of surface hydrogen evolution reaction. The catalyst is prepared by a method of firstly photo-depositing Pt on TiO 2 and then loading double photosensitizers. In the aqueous solution irradiated by visible light (lambda >400 nm) and taking triethanolamine as a sacrificial agent, the catalyst shows excellent photocatalytic hydrogen evolution activity and stability, and the hydrogen evolution rate of the optimal example (2 FMPA-BT-BA and Y6 co-sensitization) can reach 55.47 mmol g ‑1 h ‑1 . The invention provides a new material for efficiently utilizing solar energy to prepare hydrogen by photocatalysis.

Inventors

  • LI FEI
  • GAO HUA
  • LI XIAONA

Assignees

  • 大连理工大学

Dates

Publication Date
20260508
Application Date
20260129

Claims (8)

  1. 1. The double photosensitizer co-sensitized TiO 2 -Pt composite photocatalyst is characterized by comprising a titanium dioxide carrier, a platinum cocatalyst, a catalyst promoter and a catalyst promoter, wherein the platinum cocatalyst is supported on the surface of the titanium dioxide; The two organic photosensitizers co-supported on the surface of the titanium dioxide are respectively a small-molecule dye 2FMPA-BT-BA and an organic semiconductor acceptor, and the organic semiconductor acceptor is Y6 or IT4F.
  2. 2. The dual photosensitizer co-sensitized TiO 2 -Pt composite photocatalyst according to claim 1, characterized in that the total loading of the two organic photosensitizers is 400-900 μl, wherein the concentration of both photosensitizers in tetrahydrofuran is 0.5 mg/mL.
  3. 3. The dual photosensitizer co-sensitized TiO 2 -Pt composite photocatalyst according to claim 1, wherein the titanium dioxide is a P25 type TiO 2 .
  4. 4. A method for preparing the dual photosensitizer co-sensitized TiO 2 -Pt composite photocatalyst according to any one of claims 1 to 3, comprising the steps of: (1) Preparing TiO 2 -Pt, namely adding chloroplatinic acid solution and methanol into TiO 2 suspension, carrying out light reduction, separating and drying to obtain titanium dioxide with platinum loaded on the surface; (2) And (3) co-loading a double photosensitizer, namely dissolving 2FMPA-BT-BA and Y6 or IT4F in tetrahydrofuran, uniformly mixing, mixing with the TiO 2 -Pt powder obtained in the step (1), removing the solvent after ultrasonic dispersion, and drying to obtain the composite photocatalyst.
  5. 5. The method according to claim 4, wherein in the step (2), the 2FMPA-BT-BA and Y6 or IT4F are prepared into tetrahydrofuran solutions with a concentration of 0.5 mg/mL, respectively, before mixing.
  6. 6. The method according to claim 5, wherein in the step (2), the amount of the 2FMPA-BT-BA solution is 400. Mu.L, and the amount of the Y6 solution is 500. Mu.L; Or the 2FMPA-BT-BA solution is used in an amount of 400 mu L, and the IT4F solution is used in an amount of 400 mu L.
  7. 7. Use of a dual photosensitizer co-sensitized TiO 2 -Pt composite photocatalyst according to any one of claims 1 to 3 in photocatalytic water splitting hydrogen production reactions.
  8. 8. The use according to claim 7, wherein the photocatalytic water splitting hydrogen production reaction is carried out in an aqueous solution containing triethanolamine using a light source of visible light having a wavelength greater than 400 nm.

Description

Preparation and application of double-photosensitizer-loaded dye-sensitized composite catalyst Technical Field The invention belongs to the field of photocatalytic materials and new energy, and particularly relates to a composite photocatalyst for visible light driven water decomposition hydrogen production, in particular to a high-efficiency hydrogen evolution catalyst based on titanium dioxide and constructed by a double photosensitizer co-sensitization strategy, and a preparation method and application thereof. Background With the continuous growth of global energy demand and the increasing severity of environmental pollution, the development of renewable and clean novel energy technologies has become an urgent need. Solar energy is used as renewable energy with the widest distribution and the most abundant reserves, and efficient conversion and storage are important directions of scientific research. Among them, the use of solar energy to drive water to produce hydrogen gas, which can convert intermittent solar energy into chemical energy (hydrogen energy) with high energy density, is considered as one of the most potential clean energy technical routes. Among the many photocatalytic materials, titanium dioxide (TiO 2) is one of the most widely studied photocatalysts due to its excellent chemical stability, environmental friendliness, low cost, and suitable energy band positions. However, the inherent wide bandgap characteristic of TiO 2 results in its light absorption lying predominantly in the ultraviolet region. This results in very low utilization of TiO 2 in the visible and near infrared regions of the main body of the solar spectrum. To broaden the spectral response range of TiO 2, dye sensitization techniques have been introduced. The technology drives the reduction reaction by adsorbing a photosensitizing dye molecule as an "antenna" on the surface of TiO 2, absorbing visible light and generating excited state electrons, and then injecting the electrons into the conduction band of TiO 2. Currently, research is focused on single dye sensitization systems such as bipyridyl ruthenium complexes (e.g., N3, N719) or pure organic dyes. Although a certain progress is made, a single dye system still has the obvious defects that firstly, the absorption spectrum is usually narrow, the whole visible light to near infrared spectrum is difficult to cover, a great deal of solar energy waste is caused, secondly, the photo-generated electron-hole pair is easy to be compounded in the dye or at the interface of the dye and TiO 2, so that the charge separation and transmission efficiency is low, and the overall quantum efficiency is low. In recent years, organic semiconductor acceptor materials represented by Y6, ITIC and derivatives thereof (e.g., IT 4F) exhibit excellent properties in the organic photovoltaic field. The material has wide absorption spectrum, high molar absorptivity and strong absorption especially in the near infrared region of 550-800 nm, and the energy level structure is easy to regulate. If the dye can be combined with a small molecular dye to construct a complementary light absorption double-photosensitizer system, the light can be captured efficiently from a wide spectrum of visible near infrared. Meanwhile, by introducing a proper cocatalyst (such as platinum metal) on the surface of the TiO 2, electrons can be effectively captured, and the overpotential of hydrogen evolution reaction can be reduced, so that the surface reaction kinetics is accelerated, and the charge recombination is inhibited. Therefore, a novel dye sensitization composite catalyst which can cooperatively realize wide spectrum absorption, high-efficiency charge separation and rapid surface reaction is developed, and has important scientific significance and application value for improving the efficiency of solar photocatalytic hydrogen production. Based on the deep analysis of the prior art, the invention aims to systematically solve the following three key technical problems which restrict the improvement of the performance of a dye-sensitized photocatalytic system: a. The problem of low solar spectrum utilization rate is that the light absorption of the single dye sensitized TiO 2 system which is currently mainstream is generally limited to a specific wave band (such as 400-600 nm), and can not effectively capture and utilize visible light and near infrared light in a wider range (especially 600-800 nm) in the solar spectrum, so that a large amount of light energy is not converted, and the solar energy conversion efficiency has a theoretical bottleneck. B. The problem of low photo-generated charge separation and transmission efficiency is that in the existing system, after electrons generated by the excitation of a photosensitizer are injected into a conduction band of TiO 2, the migration and transmission processes are easy to be blocked. Due to the lack of efficient surface reaction sites, electrons are easily compoun