光驱动的CoOx/WO3-x光热协同催化CO2还原

杨娟; 田然; 王大钊; 戴俊; 杜智华

光驱动的CoO_x/WO_3-x光热协同催化CO₂还原

杨娟^{1, 2, 3, ,},
田然¹,
王大钊¹,
戴俊^{1, 2},
杜智华¹

1.
河南理工大学　安全科学与工程学院, 河南焦作 454003
2.
煤炭安全生产与清洁高效利用省部共建协同创新中心, 河南焦作 454003
3.
河南理工大学　化学化工学院, 河南焦作 454003

基金项目: 国家自然科学基金(52074103, U2004194)；河南省科技攻关重点项目(222102320095)；河南省教育厅重点科研项目(21 A440008)

详细信息

通讯作者:
杨娟，博士，教授，博士生导师，研究方向为光催化与能源化学　E-mail: yangjuan@hpu.edu.cn

中图分类号: O643.3
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- 被引次数: 0
出版历程
- 收稿日期: 2022-10-10
- 修回日期: 2022-11-06
- 录用日期: 2022-11-12
- 网络出版日期: 2022-12-03

Light-driven photothermal synergistic catalytic CO₂ reduction over CoO_x/WO_3-x

Juan YANG^{1, 2, 3
, ,},
Ran TIAN¹,
Dazhao WANG¹,
Jun DAI^{1, 2},
Zhihua DU¹

1.
School of Safety Science and Engineering, Henan Polytechnic University, Henan Jiaozuo 454003, China
2.
State Collaborative Innovation Center of Coal Work Safety and Clean-efficiency Utilization, Henan Jiaozuo 454003, China
3.
School of Chemistry and Chemical Engineering, Henan Polytechnic University, Henan Jiaozuo 454003, China

Funds: National Natural Science Foundation of China (No.52074103, No.U2004194); Key Science and Technology Project of Henan Province (No.222102320095); Key Scientific Research Project of Henan Province Education Department (No.21 A440008)

摘要

摘要: 基于半导体光催化CO₂还原的人工光合成技术利用清洁可持续的太阳能，在室温常压下将CO₂转化为碳基燃料，被认为是可同时缓解能源短缺和环境危机的理想策略，但因已有光催化剂对太阳光利用率不足、光生电荷复合快，致使CO₂光还原能量转换效率仍较低，严重阻碍了其实际应用。本文采用水热法并结合表面浸渍过程首次制备出无定型CoO_x/WO_3-x复合催化剂，并研究了其在可见-近红外光(Vis-NIR)照射下的CO₂催化还原性能。氧空位的引入可调控WO_3-x的电子结构，在其能带结构中形成一新的中间能级(IEL)，产生近红外光响应与催化剂表面局部温升。复合助催化剂CoO_x可在调控WO_3-x导带电势的同时，经由捕获光空穴增强光生电荷的分离与迁移。上述两方面协同作用显著增强CoO_x/WO_3-x的CO₂光还原性能，最优催化剂2.5% CoO_x/WO_3-x可见-近红外光照射3h的CO与CH₄产生量分别可达78.2与19.7 μmol·g^-1，且Vis-NIR照射下的C1产物生成量大于NIR与Vis之和，表明CO₂还原性能的提升主要归因于光热协同催化，对设计光驱动的CO₂还原催化剂及光热协同催化体系具有重要理论指导意义。1不同光源照射条件下的CO₂还原产物生成量(a)和CoO_x/WO_3-x光热协同催化CO₂还原性能增强机制示意图(b)
- 光催化 /
- WO_3-x /
- CoO_x /
- CO₂光还原 /
- 光热协同
Abstract: The conversion of CO₂ into carbon-based fuels through artificial photosynthesis technology based on semiconductor photocatalytic reduction has been identified as an ideal strategy to alleviate energy shortage and environmental crisis. However, due to insufficient utilization of solar energy and rapid recombination of photogenerated charges for the reported photocatalysts, the energy conversion efficiency of CO₂ photoreduction is still low. Amorphous CoO_x/WO_3-x composite photocatalysts were synthesized by a hydrothermal method combining with surface impregnation process for the first time. Crystal phase composition, microstructure, optical absorption properties and oxygen vacancy defects of the prepared catalysts were systematically characterized by XRD, TEM, XPS, EPR and UV-Vis-NIR DRS. The results of CO₂ photoreduction experiments show that only 3.2 μmol·g⁻¹ CH₄ can be detected when using WO_3-x as a catalyst after Vis-NIR light irradiation for 3 h, whereas introducing CoO_x can significantly boost the CO₂ photocatalytic reduction performance of WO_3-x. Under the same experimental conditions, the yield of CO and CH₄ on 2.5% CoO_x/WO_3-x catalyst can reach 78.2 and 19.7 μmol·g⁻¹ respectively. Introducing oxygen vacancies can form a new intermediate energy level in the band structure of WO_3-x, which enhances NIR absorption and causes local temperature rise of the catalysts surface. Incorporating CoO_x contributes to enhance the separation and migration of photogenerated charges, and meanwhile can regulate the conduction-band potential of WO_3-x. The synergistic effect of photothermal effect and CoO_x cocatalyst is the primary reason for the promoted performance of CO₂ photocatalytic conversion. Additionally, the composite photocatalysts CoO_x/WO_3-x shows excellent long-term catalytic and structural stability.
- Photocatalysis /
- WO_3-x /
- CoO_x /
- CO₂ photoreduction /
- photothermal synergy

HTML全文

图 1 CoO_x/WO_3-x催化剂制备过程示意图

Figure 1. Schematic diagram of CoO_x/WO_3-x catalysts preparation process

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图 2 CoO_x/WO_3-x样品的XRD谱图

Figure 2. XRD patterns of CoO_x/WO_3-x samples

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图 3 (a) 单一WO_3-x的TEM图像；(b)~(d) 2.5% CoO_x/WO_3-x样品的TEM与HRTEM图像

Figure 3. (a) TEM image of bare WO_3-x; (b)~(d) TEM and HRTEM images of 2.5% CoO_x/WO_3-x sample

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图 4 (a) 2.5% CoO_x/WO_3-x样品的HAADF-STEM图与(b)~(d)对应的元素Mapping图

Figure 4. (a) HAADF-STEM, (b)~(d) element mapping images of 2.5% CoO_x/WO_3-x sample

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图 5 单一WO_3-x与2.5% CoO_x/WO_3-x的XPS全谱(a)、W 4f高分辨XPS谱(b)和O 1s高分辨XPS谱(c)、2.5% CoO_x/WO_3-x的Co 2p高分辨XPS谱(d)

Figure 5. XPS survey spectra of bare WO_3-x and 2.5% CoO_x/WO_3-x (a), high-resolution W 4f XPS spectra (b) and O 1s XPS spectra of WO_3-x and 2.5% CoO_x/WO_3-x (c), high-resolution Co 2p XPS spectrum of 2.5% CoO_x/WO_3-x (d)

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图 6 WO₃、WO_3-x与2.5% CoO_x/WO_3-x的室温ESR谱

Figure 6. Room temperature ESR spectra of WO₃, WO_3-x and 2.5% CoO_x/WO_3-x

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图 7 WO₃、WO_3-x与2.5% CoO_x/WO_3-x的紫外-可见-近红外吸收光谱(a)及相应的(αhv)²对hv曲线(b)~(d)

Figure 7. (a) UV-Vis-NIR absorption spectra of WO₃, WO_3-x and 2.5% CoO_x/WO_3-x, (b)~(d) the corresponding (αhv)² vs. hv curves

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图 8 (a) 不同反应条件下C1产物与O₂生成量，(b) 可见-近红外光照射下不同CoO_x/WO_3-x催化剂的C1产物生成量，(c) 不同光源照射条件下的C1产物生成量，(d) 可见-近红外光照射下2.5% CoO_x/WO_3-x的长期催化稳定性

Figure 8. Generation amount of C1 products and O₂ under different reaction conditions (a), generation amount of C1 products on different CoO_x/WO_3-x under Vis-NIR light (b) and under different light source irradiation (c), long-time catalytic stability of 2.5% CoO_x/WO_3-x under Vis-NIR light (d)

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图 9 36小时CO₂光还原实验后2.5% CoO_x/WO_3-x催化剂的(a) XRD谱图(插图为对应的TEM图像)，(b) Co 2p高分辨XPS谱图

Figure 9. (a) XRD pattern (inset is the corresponding TEM image) and (b) high-resolution Co 2p XPS spectrum of the used 2.5% CoO_x/WO_3-x catalyst after 36 h CO₂ photoreduction

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图 10 (a) WO_3-x与(b) 2.5% CoO_x/WO_3-x催化剂的莫特-肖特基曲线

Figure 10. Mott-Schottky plots of (a) WO_3-x and (b) 2.5% CoO_x/WO_3-x catalysts

C^-2−Reciprocal of interface capacitance squared, E_CB−conduction band potential, E_fb−flat band potential

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图 11 单一WO_3-x、2.5% CoO_x/WO_3-x和4.0% CoO_x/WO_3-x样品的瞬态光电流响应谱(a)与电化学阻抗谱(b)

Figure 11. Transient photocurrent response spectra (a) and electrochemical impedance spectra (b) of bare WO_3-x, 2.5% CoO_x/WO_3-x and 4.0% CoO_x/WO_3-x samples

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图 12 光驱动的CoO_x/WO_3-x光热协同催化CO₂还原性能增强机制示意图

Figure 12. Performance enhancing mechanism diagram of light driven photothermal synergistic catalytic CO₂ reduction over CoO_x/WO_3-x

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表 1 CoO_x/WO_3-x复合催化剂中Co元素的实测含量

Table 1. Actual content of Co element in CoO_x/WO_3-x composite catalysts

Sample	Addition content of Co/wt%		Measured content of Co/wt%
0.8% CoO_x/WO_3-x		0.8		0.79
1.6% CoO_x/WO_3-x		1.6		1.57
2.5% CoO_x/WO_3-x		2.5		2.48
3.2% CoO_x/WO_3-x		3.2		3.17
4.0% CoO_x/WO_3-x		4.0		3.95

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表 2 CO₂光催化还原产物生成速率的比较

Table 2. Comparison of products generation rate for CO₂ photocatalytic reduction

Photocatalysts	CO yield/(μmol·g⁻¹·h⁻¹)	CH₄ yield/(μmol·g⁻¹·h⁻¹)	Reaction conditions	Reference
MoO_3-x	10.3	2.08	300 W Xe lamp UV-Vis-IR	J Mater Chem A 2019 Ref.[20]
Bi₂S₃/UiO-66	25.6	––	300 W Xe lamp UV-Vis-IR	Appl Catal B-Environ 2020 Ref.[17]
C-doped WO_3-x	23.2	1.01	300 W Xe lamp an AM1.5 G filter	ACS Catal 2022 Ref.[37]
Bi₄TaO₈Cl/W₁₈O₄₉	23.42	––	180 mW/cm² solar light, 393 K	Appl Catal B-Environ 2020 Ref.[42]
WO₃ nanosheets	––	1.19	300 W Xe lamp Visible light	ACS Appl Mater Inter 2012 Ref.[43]
TiO_2-x(A/B)-CoO_x	16.46	10.02	150 W UV lamp 393 K	Appl Catal B-Environ 2019 Ref. [44]
WO₃/LaTiO₂N	2.21	0.36	300 W Xe lamp Visible light	ACS Sustain Chem Eng 2021 Ref.[45]
WO_3-x/g-C₃N₄	8.3	––	500 W Xe lamp	ACS Omega 2019 Ref [46]
2.5% CoO_x/WO_3-x	26.1	6.57	300 W Xe lamp Vis-NIR	this work

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