











摘 要:為了更好地利用太陽能將CO2轉化為附加值產品,采用水煮法,合成比表面積達1 009.5 m2/g的六方氮化硼(h-BNNS),以h-BNNS和聚丙烯腈(PAN)為紡絲液原料,采用靜電紡絲法制備h-BNNS/CPAN纖維膜,然后通過真空浸漬銀鹽得到Ag/h-BNNS/CPAN復合膜,并對復合膜的形貌、元素組成、微觀結構及光電特性進行表征。結果表明:引入銀納米粒子(Ag NPs)并沒有改變h-BNNS的結構,其均勻分布在h-BNNS/CPAN復合纖維膜上;以對硝基苯酚(4-NP)還原為對氨基苯酚(4-AP)反應測定合成工藝條件對復合材料性能的影響,當焙燒溫度為220 ℃、h-BNNS含量為25%時,Ag NPs的光催化效果最好,催化劑光還原4-NP的表觀速率為0326 s-1;在以CO2還原為模型的反應中,Ag/h-BNNS/CPAN復合膜的光催化活性與納米Ag的含量成正比,當Ag NPs含量為2.0%時,光催化2 h后CO2轉化為CO的產率為181.4 μmol/g。結合Ag/h-BNNS/CPAN復合纖維膜的光電特性分析其光催化性能,可探索復合膜光催化CO2還原反應的機理,在光催化反應過程中,Ag NPs與h-BNNS/CPAN復合纖維膜間通過協同作用可實現CO2的高轉化率,為高分散納米金屬光催化劑載體的設計合成提供了有效途徑。
關鍵詞:催化化學;貴金屬光催化劑;六方氮化硼;六方氮化硼納米片;聚合物纖維膜;復合光催化劑
中圖分類號:O643.3;TB383.2
文獻標識碼:A
DOI:10.7535/hbkd.2024yx05004
Photocatalytic properties of Ag/h-BNNS/CPAN
composite fiber membranes
WANG Ruopeng1, WANG Sai1, DAI Dezhao1, LI Wenhui1, HAN Yuhe1, LU Qiong AN Jing1,2
(1.School of Sciences, Hebei University of Science and Technology, Shijiazhuang, Hebei 050018 47MgOUzzpSuxwD4qM+S74Q==, China;
2.Hebei Provincial Key Laboratory of Photoelectric Control on Surface and Interface, Shijiazhuang, Hebei 050018 , China)
Abstract:In order to make better use of solar energy to convert carbon dioxide into value-added products, we synthesized hexagonal boron nitride (h-BNNS) with a specific surface area of 1 0095 m2/g by boiling method. Then h-BNNS/CPAN fiber film was prepared by electrospinning method with h-BNNS and polyacrylonitrile (PAN) as the raw materials, and then Ag/h-BNNS/CPAN composite film was prepared by vacuum impregnation of silver salt. The morphology, elemental composition, microstructure and photoelectricity characteristics of the composite film were characterized.The results showed that the structure of h-BNNS was not changed after the introduction of Ag NPS, and it was uniformly distributed on the h-BNNS/CPAN composite fiber membrane.The effect of synthesis conditions on the properties of the composite was determined by the reduction of p-nitrophenol (4-NP) to p-hydroxyaniline (4-AP). It was found that the photocatalytic effect of Ag nanoparticles (Ag NPs) was the best when the calcination temperature was 220 ℃ and the content of h-BNNS was 25%. The apparent rate of photoreduction of 4-NP with the catalyst is 0326 s-1.The photocatalytic reduction performance of Ag/h-BNNS/CPAN composite film was further investigated using CO2 reduction model reaction. The results showed that the photocatalytic activity of Ag/h-BNNS/CPAN composite film was directly proportional to the content of Ag NPs. When the Ag NPs content was 20%, the photocatalytic activity of Ag/h-BNNS/CPAN composite film was directly proportional to that of Ag NPs. The yield of CO2 to CO was 1814 μmol/g after photocatalysis for 2 h.Combined with the photoelectric characteristics of Ag/h-BNNS/CPAN composite fiber film to analyze its photocatalytic performance, the mechanism of photocatalytic CO2 reduction reaction of the composite membrane can be explored, indicating that the synergistic interaction between Ag NPs and h-BNNS/CPAN composite fiber film in the photocatalytic reaction process can achieve high CO2 conversion.This study provides an effective way for the design and synthesis of highly dispersed nano-metal photocatalyst carriers.
Keywords:catalytic chemistry;
precious metal photocatalyst; hexagonal boron nitride; hexagonal boron nitride nanosheet; polymer fiber membrane; composite photocatalyst
六方氮化硼(h-BN)是一種新興的二維材料,在許多領域受到廣泛關注[1]。然而,由于其帶隙較寬(約6 eV),對紫外和可見光的吸收較弱,因而在光催化劑領域的應用受到極大限制[2]。尋找并制備具有優良光響應性、可重復使用性、低成本和高催化效率的納米復合材料,是提升光催化技術性能的關鍵[3]。多孔氮化硼納米片(h-BNNS)具有有序孔結構,且比表面積高,其帶隙與h-BN相比明顯減小[4-6]。此外,貴金屬的負載為h-BNNS提供了大量活性位點,可實現功能化改性[7]。HE等[8]將Au NPs加載到h-BNNS上制得Au NPs/h-BNNS復合材料,有效提升電子-空穴對的分離和轉移,為氮化硼基光催化劑的設計提供了依據。此方法不僅縮小了h-BN帶隙,還解決了電荷重組問題,增強了光催化性能。銀納米粒子(Ag NPs)以穩定性、低成本和易得性,廣泛應用于催化和光催化領域。Ag NPs作為摻雜劑與半導體材料復合,通過局域表面等離子體共振效應,可加速電子轉移并增強可見光吸收,提升光催化性能[9-10]。但為防止其小尺寸導致的團聚,需尋找適宜的載體確保其在表面均勻分散,以充分利用其催化性能。
利用靜電紡絲技術,可以制備直徑從幾微米至100 nm的聚合物纖維[11-12]。靜電紡絲復合膜利用了基體的高比表面積[13]和高孔隙率等優勢[14],同時,它也充當有效分散納米顆粒的優良載體。目前,納米纖維膜廣泛應用于醫療、環境和能源領域[15-16]。h-BNNS作為納米貴金屬光催化劑的優良載體,可通過靜電紡絲與PAN均相復合。因此,本研究先以高溫熱解法制備h-BNNS,再通過高壓靜電紡絲制備h-BNNS/CPAN復合纖維膜,并利用真空浸漬法負載銀離子,制得Ag/h-BNNS/CPAN光催化劑,應用于光催化4-NP還原和CO2轉化。
1 實驗部分
1.1 主要原料
三聚氰胺、硼氫化鈉、對硝基苯酚,分析純,上海阿拉丁生化科技股份有限公司提供;聚丙烯腈、N, N-二甲基甲酰胺,分析純,天津市大茂化學試劑廠提供;硼酸,分析純,上海泰坦科技股份有限公司提供;硝酸銀,分析純,天津東聚隆化工技術開發有限公司提供。
1.2 h-BNNS的制備
在裝有800 mL蒸餾水的燒杯中依次加入18.92 g三聚氰胺和18.55 g硼酸,使三聚氰胺、硼酸物質的量比為1∶2。將燒杯置于水浴鍋中加熱至98 ℃,恒溫攪拌至完全溶解后,降溫至80 ℃靜置保溫6 h,自然冷卻,靜置過夜,洗滌、抽濾,于恒溫60 ℃下烘干至恒重,得到白色纖維狀h-BNNS前驅體,記為M·2B。將制備好的M·2B在100 mL/min流量下的N2氣氛中,以5 ℃/min的速率在高溫管式爐中程序升溫至1 050 ℃焙燒4 h,以3 ℃/min程序降溫至300 ℃后,冷卻至室溫,得到白色h-BNNS粉末。
1.3 h-BNNS /PAN復合纖維膜的制備
稱取一定質量的PAN,在緩慢攪拌下溶于DMF溶液中,持續攪拌12 h,再靜置12 h得到10% PAN紡絲液。稱取一定質量的h-BNNS(h-BNNS占PAN質量分數為25%),溶于已配好的10% PAN紡絲分散液中,超聲20 min,攪拌均勻得到h-BNNS/PAN紡絲液。將配好的紡絲液在高壓靜電紡絲機中靜電紡絲得到h-BNNS/PAN纖維膜。再將纖維膜置于管式爐中,N2流量保持50 mDYdGcvY9NrZalGN2bJdW2A==L/min,升溫速率為2 ℃/min,于220 ℃恒溫焙燒2 h,最終得到不溶于水的h-BNNS/CPAN復合膜。
1.4 Ag/h-BNNS/CPAN復合物的制備
稱取一定質量的h-BNNS/CPAN復合纖維膜置于燒杯中,再量取一定體積的AgNO3水溶液放入上述燒杯中,將燒杯置于真空干燥箱中,室溫下真空浸漬2 h,然后將所制備的復合纖維膜平鋪于平皿內于60 ℃真空烘干,最終得到Agx/h-BNNS/CPAN復合纖維膜,其中x代表銀的質量分數。
1.5 Ag/h-BNNS/CPAN復合纖維膜的結構及性能表征
比表面積測試與樣品的顆粒大小、形狀及孔結構相關。將待測樣品真空干燥后脫氣處理。樣品的比表面積可以通過計算得到,而待測樣品顆粒是否分散均勻可通過樣品比表面積大小來反映。本實驗選用吸附儀型號為TriStar II 3020,選用日本電子公司HITACHI產的S4800-I型場發射掃描電鏡(SEM)對噴金后Ag/h-BNNS/CPAN進行形貌分析,選用日本產JEM-2100透射電子顯微鏡對Ag/h-BNNS/CPAN復合纖維膜進行形貌觀察和物相分析,依據測試結果得到材料形貌、物相及晶系。
選用日本Rigaku公司D/max 2500型儀器對所測樣品的表征圖譜和已知晶態譜圖進行對比,確定復合纖維膜物相組成和結構;選用日本Shimadzu公司IR Prestige-21型紅外光譜儀測定鑒別化合物類型;選用日本IR Prestige-21型Raman光譜儀對復合纖維膜碳鏈或環結構信息進行表征;選用PHI-1600型X射線電子能譜分析(XPS)對復合聚合物纖維膜的元素成分、化學狀態和分子結構等進行分析;選用TG-204型熱重測試儀對復合聚合物纖維膜結構及熱穩定性進行分析。測試復合纖維膜光催化劑中Ag NPs的實際含量選用儀器型號為安捷倫7800,通過電感耦合等離子體質譜分析測定催化劑中金屬的實際含量。
選用熒光光度儀測試樣品的穩態熒光發射光譜強度。熒光屬于發光光譜,是在輻射吸收之后分子立即發射出的光,通常所研究的熒光光譜隸屬于電子吸收光譜的范疇,電子態轉化為激發態由激發單線態以及激發三線態構成。選用測試儀器型號為UV-2550,紫外可見漫反射吸收光譜(UV-vis)主要用于對復合聚合物纖維膜的光吸收性能進行測試分析。
選用Solartron 1255 B頻率響應分析器及 Solartron SI 1287電化學界面,以0.1 mol/L的KCl溶液為電解液,FTO為基底的電極為工作電極。區別于傳統的光電化學研究方法,瞬態光電流測試手段主要研究的是復合分子材料內部光生電子以及空穴的分離聚合能力,使用該方法對試驗樣品進行光能吸收測試可以觀察到光電流的產生與全部變化過程。利用電化學方法對此光電流進行測試即為瞬態光電流測試。選用日本JES-FA300電子自旋共振譜儀測定聚合物纖維膜的氧空位狀態,通過ESR測試可以獲得催化劑的表面性質及反應機理。
1.6 光催化活性評價
本實驗以光催化還原CO2為反應模型,探究復合纖維膜還原CO2的能力。具體操作步驟如下:首先稱取20 mg復合纖維膜平鋪于樣品盤中,加入2.5 mL的蒸餾水,然后放入干燥箱中于70 ℃烘干備用。將一盛有2.5 mL蒸餾水的托盤放在反應釜底部為反應提供氫源,再將盛有復合纖維膜的樣品盤置于其上,密封,抽真空后通入高純CO2至常壓,此操作需重復3次。開啟循環冷凝水保持反應溫度為25 ℃,采用300 W的氙燈模擬太陽光,光照即開始計時,每間隔2 h用注射器取1 mL反應氣體注射到GC-7900氣相色譜儀中,測定CO的生成量。反應結束后,取出樣品盤并將其放入烘箱烘干水分,在托盤中重新放入2.5 mL的蒸餾水,按上述方法重復測試實驗。如此循環10次,探究復合纖維膜的穩定性。
2 結果與討論
2.1 Ag/h-BNNS/CPAN復合材料的形貌和微觀結構
圖1為h-BNNS、PAN、CPAN、復合纖維膜h-BNNS/PAN、h-BNNS/CPAN和Ag2.0/h-BNNS/CPAN的SEM照片及Ag2.0/h-BNNS/CPAN中各元素地圖和EDX光譜分析圖。
如圖1 a)所示,h-BNNS的SEM照片顯示樣品呈棒狀結構,表面粗糙,邊緣有褶皺,且具有豐富的孔道。圖1 b)和圖1 c)分別為PAN和CPAN的SEM照片,顯示纖維膜中的絲狀結構表面光滑平整[17],焙燒前后的PAN纖維形貌無明顯差別。圖1 d)和圖1 e)為h-BNNS/PAN和h-BNNS/CPAN焙燒前后的SEM照片,可以觀察到h-BNNS均勻分布在納米纖維表面,且焙燒前后h-BNNS/PAN和h-BNNS/CPAN在形貌上無明顯區別。從圖1 f)可以看到h-BNNS/CPAN纖維膜表面附著有細小顆粒,很有可能為Ag NPs。圖1 g)中SEM-EDX能譜圖顯示Ag含量為0.51%,證實Ag NPs成功載入復合纖維。由于SEM-EDX僅能測定表面銀含量而無法測定整體復合膜中的實際含量,故通過電感耦合等離子質譜(ICP)測定了設計銀含量為2.0%的Ag/h-BNNS/CPAN復合纖維膜中銀的實際含量為0.96%。圖1 g)中元素地圖顯示,B、N、C、O、Ag各元素均勻分布在h-BNNS/CPAN復合纖維膜中。
圖2 a)為Ag2.0/h-BNNS/CPAN復合纖維膜的TEM照片。由圖2 a)可以清楚觀察到Ag2.0/h-BNNS/CPAN復合纖維膜的微觀結構,圖中的黑點,即Ag NPs,均勻分散于h-BNNS/CPAN復合纖維膜中,平均粒徑不足10 nm。圖2 a)中的內插圖是放大10倍后的高分辨率TEM照片,圖中顯示銀晶體的晶格間距為024 nm,對應面心立方銀的(111)晶面[18-20]。圖2 b)為SAED圖,通過衍射斑點進一步證實Ag NPs為面心立方的單晶結構。
圖3為h-BNNS、CPAN、h-BNNS/CPAN和Agx/h-BNNS/CPAN不同銀含量纖維膜的XRD譜圖。在衍射角2θ為26.8°處具有明顯的衍射峰,對應于h-BNNS/CPAN和不同銀含量Ag/h-BNNS/CPAN纖維膜中h-BNNS的(002)晶面;Ag2.0/h-BNNS/CPAN在衍射角2θ為41.6°位置處具有相對較弱的衍射峰,對應h-BNNS標準卡的(100)晶面;不同銀含量Ag/h-BNNS/CPAN復合纖維膜在2θ為38.1°和44.3°的弱衍射峰,分別對應于納米Ag的(111)晶面和(200)晶面[20]。結果表明Ag NPs成功負載于h-BNNS/CPAN纖維膜上。
2.2 Ag2.0/h-BNNS/CPAN復合材料的組成分析
采用FTIR光譜測試可進一步探究復合纖維膜的組成。圖4 a)為h-BNNS、PAN、CPAN、h-BNNS/PAN、h-BNNS/CPAN和Ag2.0/h-BNNS/CPAN的FTIR譜圖。圖4 a)中在3 448 cm-1處的寬吸收峰為樣品物理吸附水中—OH的伸縮振動峰;2 925 cm-1處屬于飽和C—H鍵的伸縮振動峰;2 243 cm-1處PAN和h-BNNS/PAN吸收峰較CPAN和h-BNNS/CPAN焙燒后的吸收峰更加明顯,其原因是PAN環化導致C≡N吸收峰[21-23]變弱,而在1 382 cm-1處產生對應C—N伸縮振動的新吸收峰[24-25]。從圖4 a)可以觀察到引入Ag后,并沒有出現吸收峰的消失與增加,且峰位無偏移,說明Ag并未破壞h-BNNS/CPAN各組成之間的關系。圖4 b)為PAN、CPAN和Ag2.0/h-BNNS/CPAN的Raman譜圖。由圖4 b)可以看出,1 352 cm-1處對應h-BNNS中CC鍵伸縮振動峰,在1 554 cm-1處Ag2.0/h-BNNS/CPAN與CPAN都有CN鍵伸縮振動峰,但Ag2.0/h-BNNS/CPAN與CPAN較PAN的C≡N鍵峰明顯變弱[26],更進一步證明復合纖維膜經焙燒后,其組成中的PAN環化為CPAN。
圖5 a)為h-BNNS、h-BNNS/CPAN和Ag2.0/h-BNNS/CPAN的XPS譜圖。圖中顯示復合纖維膜中B元素含量明顯低于C、N和O元素,原因是復合纖維中純h-BNNS的設計含量僅為PAN的5%。此外,Ag2.0/h-BNNS/CPAN復合膜表面Ag光電子能譜峰的存在證明纖維膜中成功引入了Ag NPs。圖5 b)—e)分別為Ag2.0/h-BNNS/CPAN復合纖維膜中B 1s、C 1s、N 1s和Ag 3d的能譜圖。B 1s能譜中190.7 eV和192.1 eV結合能分別對應于sp2雜化的B—N和B—O。C 1s能譜圖中的285.8 eV和287.1 eV這2種結合能分別對應于C—N和N—CN。Ag 3d能譜中374.8 eV和368.8 eV結合能分別對應Ag 3d5/2和Ag 3d3/2,表明Ag+成功還原為Ag0,因此復合纖維膜中負載有單質銀[27]。
2.3 Ag/h-BNNS/CPAN復合材料的光電性能
采用UV-vis DRS可以測定復合纖維膜的光吸收性能。圖6 a)為h-BNNS、PAN、CPAN、h-BNNS/CPAN及不同銀含量Ag/h-BNNS/CPAN復合纖維膜光催化材料的UV-vis DRS譜圖。與純PAN相比,環化后CPAN由于具有離域的共軛結構,因而其在420~800 nm范圍內對光的吸收能力增強。此外,h-BNNS與CPAN之間的協同作用在很大程度上提高了光吸收能力[28-29]。隨著Ag NPs的引入,復合光催化劑的光吸收能力明顯增強,并且Ag負載量越多,Ag表面等離子體共振效應逐漸增強,復合纖維膜對可見光的吸收能力也隨之增強。圖6 b)為h-BNNS、PAN、CPAN、h-BNNS/CPAN及不同銀含量Ag/h-BNNS/CPAN復合纖維膜的PL譜圖。與純h-BNNS和PAN相比,環化后的CPAN及復合光催化劑的熒光強度明顯減弱。這是由于CPAN與h-BNNS中的共軛結構協同作用,有效降低了光生載流子的復合幾率,提高了載流子的傳輸速率。由于Ag具有優良的導電性,引入Ag NPs后,Agx/h-BNNS/CPAN復合纖維膜中光生載流子的傳輸速率進一步增大,從而使復合膜的光催化性能得到顯著提高。
通過交流阻抗(EIS)分析能夠比較不同組成復合纖維膜的電子遷移效率。圖7 a)為h-BNNS/CPAN和不同銀含量Ag/h-BNNS/CPAN復合纖維膜的EIS譜圖。已知圓弧半徑的大小與光生載流子的分離效率成反比[30]。從圖7 a)可以看到負載Ag NPs后復合纖維膜的圓半徑明顯減小,且隨著Ag含量的增加逐漸變小,說明引入Ag NPs能夠顯著提高復合膜中載流子的遷移速率。從圖7 b)可知,CPAN、h-BNNS/CPAN及不同銀含量Ag/h-BNNS/CPAN都會產生光電信號。載Ag后的復合膜相較于h-BNNS/CPAN、CPAN具有較高的光電流響應,說明復合膜中Ag NPs能夠促進光生電子-空穴的分離,從而提高納米纖維膜的光催化活性。
2.4 Agx/h-BNNS/CPAN復合材料的光催化性能
圖8 a)為h-BNNS/CPAN和Agx/h-BNNS/CPAN復合纖維膜光催化CO2還原反應的性能測試圖。由圖8 a)可以看出,載Ag NPs后的復合膜光催化活性明顯優于未載銀的h-BNNS/CPAN,當銀的設計負載量為2.0%時復合纖維膜的光催化性能最佳,其光催化CO2還原為CO的產率達到181.4 μmol/(g·h)。然而,當Ag含量過多(超過3.0%)時,小尺寸的納米銀顆粒發生團聚,導致復合光催化劑中活性位點的數量不僅未增加反而有所減少,因此Ag設計負載量為3.0%時的光催化活性相較2.0%有所降低。圖8 b)為Ag2.0/h-BNNS/CPAN復合纖維膜光催化還原CO2的循環穩定性測試數據圖。結果顯示,Ag2.0/h-BNNS/CPAN復合纖維膜重復使用10次后,纖維膜仍然具有光催化CO2還原的能力;同時,數據也顯示在光催化循環過程中出現催化效率不穩定的現象,其原因與Ag2.0/h-BNNS/CPAN復合纖維膜在使用過程中膜的形態難以控制有關。總之,以上數據說明納米復合纖維膜具有良好的循環穩定性。
2.5 Ag/h-BNNS/CPAN復合材料的光催化機理分析
圖9為根據UV-vis DRS譜圖計算得到的h-BNNS和h-BNNS/CPAN的禁帶寬度計算圖及相應的價帶VBS譜圖。由圖9 a)和圖9 b)可知,純h-BNNS和h-BNNS/CPAN的禁帶寬度分別為4.23 eV和2.17 eV。
因此,h-BNNS與CPAN復合后所得到的復合纖維的帶隙明顯縮小,表明h-BNNS/CPAN具有更強的可見光驅動效應,能夠在可見光照射下推動光催化反應的進行。如圖9 c)和圖9 d)所示,利用XPS對h-BNNS和h-BNNS/CPAN進行價帶譜分析[30],從VBS譜圖中可以看出,h-BNNS的價帶能量為1.86 eV,而h-BNNS/CPAN的價帶能量為1.89 eV,較h-BNNS有所升高。根據價帶能量及禁帶寬度(Eg)可計算出h-BNNS/CPAN的導帶電位邊緣為-0.28 eV(vs.NHE),而光電子和H+將CO2轉化為CO時對應的還原電勢為-0.2 eV(vs.NHE)。因此,Ag/h-BNNS/CPAN復合纖維膜有足夠的還原能力,在可見光照射下催化CO2轉化為CO。
用ESR檢測復合光催化劑中的氧空位狀態。如圖10所示,負載Ag NPs后的復合纖維膜光催化劑的ESR信號明顯高于h-BNNS/CPAN信號,這是因為Ag NPs的引入不僅降低了光生電子-空穴的復合幾率[26],還顯著提高了載流子的傳輸速率。此外,ESR信號與Ag含量成正比,進一步證實Ag NPs作為復合纖維膜光催劑的活性位點,加快了光催化CO2還原為CO的反應速度。
鑒于以上數據分析,探索出Ag/h-BNNS/CPAN復合纖維膜光催化CO2還原反應的機理,詳見圖11。
如圖11所示,Ag/h-BNNS/CPAN復合纖維膜在光照射下所吸收的光能滿足其自身激發所需的能量,此時電子從膜光催化劑的價帶躍遷至導帶,并遷移到催化劑的表面與CO2相結合。在價帶上留下空穴(h+),空穴與水結合在一起就會產生一個質子(H+),光激發電子和H+形成H2,電子與H+都有助于CO2還原為CO。因此,Ag NPs在h-BNNS/CPAN復合纖維膜上的均勻分散及其在光催化過程中與基體產生的協同作用,都可以有效降低光生電子-空穴的重組幾率,使更多的電子參與到光催化還原CO2的反應中,提高反應速率。Ag/h-BNNS/CPAN復合物光催化CO2還原為CO的反應過程如下:
2H++2e-→H2 ,
H2O→1/2O2+2H++2e- ,
CO2+2H++2e-→CO+H2O 。
3 結 語
以h-BNNS、PAN、AgNO3為主要材料,采用靜電紡絲技術制備了h-BNNS/CPAN復合纖維膜,通過真空浸漬法將Ag負載于h-BNNS/CPAN復合纖維膜中,得到Ag NPs均勻分散的納米復合纖維膜光催化劑。組成和微觀結構分析表明,具有較大表面積的多孔結構復合纖維膜顯著提高了小尺寸Ag NPs在基體材料上的穩定性,使其充分發揮等離子共振效應,并與具有共軛結構的h-BNNS/CPAN基體產生協同催化作用,使得光生電子-空穴的分離效率和載流子的傳輸速率得到明顯提升。因此,Ag/h-BNNS/CPAN納米復合纖維膜能夠實現高效而穩定的光催化CO2還原反應。
本研究通過靜電紡絲實現了納米材料h-BNNS和Ag NPs在聚合物基體材料上的穩定負載,為有機-無機納米光催化劑的有效復合及性能研究奠定了實驗基礎。然而,有關復合纖維膜有序孔結構的調控及其多晶結構的形成機理還需要進一步研究。
參考文獻/References:
[1] KHAN M H,HUANG Zhenguo,XIAO Feng,et al.Synthesis of large and few atomic layers of hexagonal Boron nitride on melted Copper[J].Scientific Reports,2015.DOI:10.1038/srepo7743.
[2] 金小愉.氮化碳的形貌和結構調控及其光催化降解典型PPCPs的機制研究[D].廣州:廣東工業大學,2022.
JIN Xiaoyu.The Morphology and Structure Regulation of Carbon Nitride and the Mechanism of Photocatalytic Degradation of Typical PPCPs[D].Guangzhou:Guangdong University of Technology,2022.
[3] 盧瓊,王爭爭,尚云云,等.氮化硼作為催化劑載體的功能化改性及其應用進展[J].河北科技大學學報,2022,43(1):59-69.
LU Qiong,WANG Zhengzheng,SHANG Yunyun,et al.Functional modification and application progress of Boron nitride as catalyst support[J].Journal of Hebei University of Science and Technology,2022,43(1):59-69.
[4] GENG Dechao,ZHAO Xiaoxu,ZHOU Ke,et al.From self-assembly hierarchical h-BN patterns to centimeter-scale uniform monolayer h-BN film[J].Advanced Materials Interfaces,2019. DOI:10.1002/admi.201801493.
[5] KUMARI S,CHOUHAN A,SHARMA O P,et al.Alkali-assisted hydrothermal exfoliation and surfactant-driven functionalization of h-BN nanosheets for lubrication enhancement[J].ACS Applied Nano Materials,2021,4(9):9143-9154.
[6] AKHTAR M W,KIM J S,MEMON M A,et al.Hybridization of hexagonal boron nitride nanosheets and multilayer graphene:Enhanced thermal properties of epoxy composites[J].Composites Science and Technology,2020.DOI: 10.1016/j.compscitech.2020.108183.
[7] CHEN Liangchen,LIU Min,CHEN Yutong,et al.2D Boron nitride supported Cu2O promotes photocatalytic nitrogen fixation at normal temperature and pressure[J].Catalysis Science & Technology,2023,13(9):2802-2809.
[8] HE Yangqing,XU Na,JUNIOR L B,et al.Construction of AuNPs/h-BN nanocomposites by using Gold as interfacial electron transfer mediator with highly efficient degradation for levofloxacin hydrochloride and hydrogen generation[J].Applied Surface Science,2020.DOI: 10.1016/j.apsusc.2020.146336.
[9] RAZA W,AHMAD K,KHAN R A,et al.Ag decorated ZnO for enhanced photocatalytic H2 generation and pollutant degradation[J].International Journal of Hydrogen Energy,2023,48(75):29071-29081.
[10]LI Xinru,SUN Nan,BAI Yaoning,et al.High photocatalytic hydrogen production of Ag@TiO2 with different sizes by simple chemical synthesis[J].Langmuir,2023,39(9):3350-3357.
[11]溫伊博,沙慧,崔眠,等.氮化硼基半導體復合材料在光催化中的應用進展ju9flMtVfBxSf/qnUdQv/Q7dx0epkk1zpBQKZ/GHX1E=[J].山東化工,2023,52(15):90-92.
WEN Yibo,SHA Hui,CUI Mian,et al.Application progress of BN-based semiconductor compositesin photocatalysis[J].Shandong Chemical Industry,2023,52(15):90-92.
[12]王偉佳.微納氮化硼材料的表面改性及性能研究[D].天津:河北工業大學,2017.
WANG Weijia.Study on Surface Modification and Properties of Micro-Nano Boron Nitride Materials[D].Tianjin:Hebei University of Technology,2017.
[13]丁珣,韓非.多孔氮化硼對鎘和鎳的吸附及解吸特征研究[J].化工新型材料,2021,49(9):208-212.
DING Xun,HAN Fei.Study on the adsorption and desorption characteristics of Cd and Ni by porous boron nitride[J].New Chemical Materials,2021,49(9):208-212.
[14]LIU Qiuwen,CHEN Cheng,DU Man,et al.Porous hexagonal Boron nitride sheets:Effect of hydroxyl and secondary amino groups on photocatalytic hydrogen evolution[J].ACS Applied Nano Materials,2018,1(9):4566-4575.
[15]CAKMAK Y,CANBOLAT M F,CAKMAK E,et al.Production and characterization of boron nitride-doped nanofiber mats created through electrospinning[J].Journal of Industrial Textiles,2018,47(6):993-1005.
[16]BUER A,UGBOLUE S C,WARNER S B.Electrospinning and properties of some nanofibers[J].Textile Research Journal,2001,71(4):323-328.
[17]LIU Zhankai,YAN Bing,MENG Shengyan,et al.Plasma tuning local environment of hexagonal Boron nitride for oxidative dehydrogenation of propane[J].Angewandte Chemie,2021,60(36):19691-19695.
[18]MATYSIAK W,TANSI T,JARKA P,et al.Comparison of optical properties of Pan/TiO2,Pan/Bi2O3,and Pan/SbSi nanofibers[J].Optical Materials,2018,83:145-151.
[19]ZHANG Peng,SHAO Changlu,ZHANG Zhenyi,et al.In situ assembly of well-dispersed Ag nanoparticles (AgNPs) on electrospun carbon nanofibers (CNFs) for catalytic reduction of 4-nitrophenol[J].Nanoscale,2011,3(8):3357-3363.
[20]LI Meixiu,HUANG Lei,WANG Xiaoxia,et al.Direct generation of Ag nanoclusters on reduced graphene oxide nanosheets for efficient catalysis,antibacteria and photothermal anticancer applications[J].Journal of Colloid and Interface Science,2018,529:444-451.
[21]LI Ziyu,JIA Zhigang,NI Tao,et al.Green and facile synthesis of fibrous Ag/cotton composites and their catalytic properties for 4-nitrophenol reduction[J].Applied Surface Science,2017,426:160-168.
[22]ZHAN Yifei,LAN Jianwu,SHANG Jiaojiao,et al.Durable ZIF-8/Ag/AgCl/TiO2 decorated PAN nanofibers with high visible light photocatalytic and antibacterial activities for degradation of dyes[J].Journal of Alloys and Compounds,2020.DOI: 10.1016/j.jallcom.2019.153579.
[23]王艷芝,張玲杰,張一風,等.電紡制備聚丙烯腈/氮化硼雜化復合纖維及其結構、性能研究[J].材料導報,2020,34(12):12158-12162.
WANG Yanzhi,ZHANG Lingjie,ZHANG Yifeng,et al.Study on preparation,structure and properties of polyacrylonitrile/Boron nitride hybrid composite fibers via electrospinning[J].Materials Review,2020,34(12):12158-12162.
[24]MEYER N,RENDERS C,LANCKMAN R,et al.Gold as active phase of BN-supported catalysts for lactose oxidation[J].Applied Catalysis A:General,2015,504:549-558.
[25]HOU Feng,LI Yong,GAO Yanting,et al.Non-metal Boron modified carbon nitride tube with enhanced visible light-driven photocatalytic performance[J].Materials Research Bulletin,2019,110:18-23.
[26]LUO Qingzhi,8adc63193db962cff573a6e1272028ed49c688270e2a6214811faefe2044d21aYANG Xiaolian,ZHAO Xiaoxiao,et al.Facile preparation of well-dispersed ZnO/cyclized polyacrylonitrile nanocomposites with highly enhanced visible-light photocatalytic activity[J].Applied Catalysis. B, Environmental,2017,204:304-315.
[27]SHANG Yaru,WANG Yu,LYU Chade,et al.A broom-like tube-in-tube bundle O-doped graphitic carbon nitride nanoreactor that promotes photocatalytic hydrogen evolution[J].Chemical Engineering Journal,2022.DOI: 10.1016/j.cej.2021.133898.
[28]SADASIVAM R,SANARAKUTTALAM C,GOPINATH P.Hierarchical architecture of electrospun hybrid Pan/Ag-rGO/Fe3O4 composite nanofibrous mat for antibacterial applications[J].Chemistry Select,2019,4(17):5044-5054.
[29]ZHANG Dantong,TIAN Weijun,CHU Meile,et al.B-doped graphitic carbon nitride as a capacitive deionization electrode material for the removal of sulfate from mine wastewater[J].Journal of the Taiwan Institute of Chemical Engineers,2023.DOI: 10.1016/J.JTICE.2023.104829.
[30]LI Xibao,KANG Bangbang,DONG Fan,et al.Enhanced photocatalytic degradation and H2/H2O2 production performance of S-pCN/WO2.72 S-scheme heterojunction with appropriate surface oxygen vacancies[J].Nano Energy,2021. DOI: 10.1016/J.NANOEN.2020.105671.