摘要： TiO_(2)is the dominant and most widely researched photocatalyst for environmental remediation,however,the drawbacks,such as only responding to UV light(<5%of sunlight),low charge separation efficiency,and difficulties in recycling,have severely hindered its practical application.Herein,we synthesized magnetically separable Fe_(3)O_(4)@MoS_(2)@mesoporous TiO_(2)(FMmT)photocatalysts via a simple,green,and template-free solvothermal method combined with ultrasonic hydrolysis.It is found that FMmT possesses a high specific surface area(55.09 m2·g?1),enhanced visible-light responsiveness(~521 nm),and remarkable photogenerated charge separation efficiency.In addition,the photocatalytic degradation efficiencies of FMmT for methylene blue(MB),rhodamine B(RhB),and tetracycline(TC)are 99.4%,98.5%,and 89.3%within 300 min,respectively.The corresponding degradation rates are 4.5,4.3,and 3.1 times higher than those of pure TiO_(2)separately.Owing to the high saturation magnetization(43.1 A·m^(2)·kg^(?1)),FMmT can achieve effective recycling with an applied magnetic field.The improved photocatalytic activity is closely related to the effective transport of photogenerated electrons by the active interlayer MoS_(2) and the electron–hole separation caused by the MoS_(2)@TiO_(2)heterojunction.Meanwhile,the excellent light-harvesting ability and abundant reactive sites of the mesoporous TiO_(2)shell further boost the photocatalytic efficiency of FMmT.This work provides a new approach and some experimental basis for the design and performance improvement of magnetic photocatalysts by innovatively incorporating MoS2 as the active interlayer and integrating it with a mesoporous shell.

摘要： 采用密度泛函理論方法對MoS_(2)完整表面、吸附式摻雜和替換摻雜缺陷MoS_(2)表面(Fe-MoS_(2)、Ir-MoS_(2))的構(gòu)型、電子結(jié)構(gòu)進行了研究.結(jié)果表明:通過比較Fe、Ir原子吸附的吸附能,發(fā)現(xiàn)Ir比Fe在表面的吸附性更強,且在Mo原子的上方吸附最強,電子態(tài)密度分析說明了在Z方向上,Mo原子的4d_(yz)、4d_(z)^(2)、4d_(xz)軌道與Ir原子的5d_(yz)、5d_(z)^(2)、5d_(xz)態(tài)密度峰存在不同程度的混合,特別是d_(z)^(2)軌道之間存在明顯混合;Fe、Ir金屬原子摻雜替換本征表面MoS_(2)的S、Mo原子的計算結(jié)果顯示,單層MoS_(2)的S位置更容易被替換形成摻雜體系,S位摻雜體系穩(wěn)定性強于在Mo位摻雜體系,且電子態(tài)密度計算顯示摻雜替換S原子后金屬Ir有效調(diào)控了MoS_(2)的電子結(jié)構(gòu),激活了替換原子Ir附近Mo的反應(yīng)活性.

摘要： 以鉬酸鈉、硫脲和三聚氰胺為原料,采用水熱合成法制備了g-C_(3)N_(4)-MoS_(2)異質(zhì)結(jié)復(fù)合材料,研究了g-C_(3)N_(4)-MoS_(2)作為催化劑降解廢水中鹽酸四環(huán)素(TC)的性能,考察了m(C_(3)N_(4))∶m(MoS_(2))、TC模擬廢水質(zhì)量濃度及催化劑用量對降解TC的影響。實驗結(jié)果表明,無需光照,g-C_(3)N_(4)-MoS_(2)作為催化劑對TC表現(xiàn)出良好的降解性能,黑暗條件下降解60 min,添加25 mg g-C_(3)N_(4)-MoS_(2)(m(C_(3)N_(4))∶m(MoS_(2))=1∶3)催化劑,對50 mL質(zhì)量濃度為10 mg/L的模擬廢水中TC的降解率達到65%。

摘要： NH_(3)是一種重要的化工原料,廣泛應(yīng)用于合成各種化工產(chǎn)品.然而,傳統(tǒng)還原N_(2)制備NH_(3)的Haber-Bosch工藝執(zhí)行條件苛刻,在消耗大量化石能源的同時產(chǎn)生嚴重環(huán)境污染.在環(huán)境條件下的電化學(xué)氮還原反應(yīng)(NRR)是一種最具前景的可持續(xù)、清潔生產(chǎn)NH_(3)的能源技術(shù),其實際應(yīng)用的核心是開發(fā)高效、價格低廉和易制備的NRR電催化劑.過渡金屬二硫族化合物(TMDCs)儲量豐富并且價格低廉,具有多變的晶體結(jié)構(gòu)和相組成、可控的形貌、缺陷設(shè)計可調(diào)節(jié)等特點,呈現(xiàn)出優(yōu)異的電催化活性,是用來替代貴金屬的理想選擇.MoS_(2)和SnS_(2)都可作為電催化劑應(yīng)用于NRR.由于金屬1T-MoS_(2)和1T’-MoS_(2)對與NRR競爭的析氫反應(yīng)(HER)具有極好的電化學(xué)活性,其NRR法拉第效率較低;盡管具有半導(dǎo)體特性的SnS_(2)能夠通過限制表面電子可及性來抑制HER,但是高過電位和較低氨產(chǎn)率仍不能令人滿意.據(jù)報道,在碳布上原位生長Mo摻雜SnS_(2)具有豐富的S空位,由于雜原子摻雜和空位工程形成了Mo-Sn-Sn三元催化位點,其NRR活性顯著增強.因此,為了抑制競爭反應(yīng)以提高NRR的法拉第效率,本文設(shè)計并制備了一種獨特的無機/有機分級納米結(jié)構(gòu)用于電催化NRR.選用一種獨特的聚兩性離子液體,即側(cè)鏈同時含有咪唑鹽和磺酸基團的聚1-乙烯基-3-丙烷磺酸基咪唑鹽(PVIPS),作為界面誘導(dǎo)劑,利用離子交換作用吸附作為前驅(qū)體的Mo7O246?和Sn^(4+),誘導(dǎo)1T’-MoS_(2)和2T型六方SnS_(2)同時生長,形成獨特的MoS_(2)-SnS_(2)異質(zhì)納米片負載于PVIPS功能化的聚吡咯/氧化石墨烯(PVIPS/PPy/GO)表面.由于各組分的協(xié)同效應(yīng),得到的MoS_(2)-SnS_(2)/PVIPS/PPy/GO納米片表現(xiàn)出較好的NRR活性,其在?0.5 V(vs.RHE)時氨產(chǎn)率最佳,為16.74μg h^(?1)mg^(?1)act.,其相應(yīng)的法拉第效率為4.07%.具有半導(dǎo)體特性的SnS_(2)能夠限制表面電子的可及性,進而抑制1T’-MoS_(2)的HER過程,而具有金屬性的1T’-MoS_(2)可與SnS_(2)形成Mo-Sn-Sn三元催化活性位點,提高SnS2的NRR電催化活性.此外,高分辨透射電鏡,X射線衍射和X射線光電子能譜結(jié)果表明,MoS_(2)-SnS_(2)/PVIPS/PPy/GO在NRR使用前后存在顯著差異,這主要歸因于在NRR過程中MoS_(2)-SnS2異質(zhì)納米片發(fā)生了不可逆的晶體相變.部分1T’-MoS_(2)和SnS_(2)與N_(2)發(fā)生電化學(xué)反應(yīng)形成Mo?N和Sn?N鍵,不可逆地相轉(zhuǎn)變?yōu)镸o_(2)N和SnxNz;部分SnS_(2)由于電化學(xué)體系中電源的還原作用而不可逆地演化為SnS.本文為優(yōu)化TMDCs的制備方法及其電催化活性提供了新的設(shè)計思路.

摘要： 通過室溫下自組裝法制備g-C_(3)N_(4)二元復(fù)合物,再用水熱法制備花狀的g-C_(3)N_(4)@ZIF-8@MoS_(2)復(fù)合光催化劑。運用X射線衍射儀、掃描電子顯微鏡以及能譜儀對g-C_(3)N_(4)@ZIF-8@MoS_(2)復(fù)合材料進行結(jié)構(gòu)表征,并通過光催化降解亞甲基藍考察了其光催化性能。結(jié)果表明,g-C_(3)N_(4)@ZIF-8@MoS_(2)復(fù)合材料在水中具備良好的穩(wěn)定性和較高的催化效率,對亞甲基藍有很好的降解效果(90 min降解99%)。

摘要： 采用模板法制備MOF衍生CoS2-NiS-MoS2/Ti,利用MOF衍生結(jié)構(gòu)來提升MoS2活性位點數(shù)目以及各組分協(xié)同作用的同時,研究刻蝕溫度對制備出的CoS2-NiS-MoS2/Ti潤濕性的影響。

摘要： 二維(2D)半導(dǎo)體薄膜材料作為當代光電子器件領(lǐng)域的主力軍,大面積薄膜材料的制備則成為亟待解決的熱點問題。文章通過一種硫(S)化預(yù)生長的氧化鉬(MoO_(3))的方法實現(xiàn)大面積二硫化鉬(MoS_(2))薄膜材料的制備。區(qū)別于傳統(tǒng)化學(xué)氣相沉積(CVD)方法生長材料隨機成核的特性,文章設(shè)計利用提前在襯底上預(yù)生長MoO_(3)作為Mo源,以固定MoS_(2)薄膜的成核位點。研究結(jié)果表明,該方法可實現(xiàn)雙層的大面積MoS_(2)薄膜。進一步,將制備的雙層大面積MoS_(2)薄膜轉(zhuǎn)移到叉指電極上進行光電性能研究,在532 nm的激光照射下,實現(xiàn)103.71 mA/W的響應(yīng)度及88μs的快響應(yīng)速度。預(yù)計文章的實驗設(shè)計可推廣到其他大面積二維薄膜材料的制備中。

摘要： 本文應(yīng)用Materials Studio軟件對MoS_(2)分別進行了Si、O、N原子的替換摻雜,以探究摻雜和吸附對MoS_(2)材料的電子結(jié)構(gòu)的影響。研究發(fā)現(xiàn):穩(wěn)定性由強到弱依次為:O-MoS_(2)-H_(2)、MoS_(2)-H_(2)、N-MoS_(2)-H_(2)、Si-MoS_(2)-H_(2),即O-MoS_(2)-H_(2)的形成能最低,為相對最穩(wěn)定的結(jié)構(gòu);摻雜后體系的成鍵形式更有可能為離子鍵;吸附和摻雜均能影響MoS_(2)電子結(jié)構(gòu),MoS_(2)-H_(2)、O-MoS_(2)-H_(2)、Si-MoS_(2)-H_(2)能隙值處于0~2.0eV之間,體系表現(xiàn)為半導(dǎo)體性,N-MoS_(2)-H_(2)能隙值為0eV,體系表現(xiàn)為金屬性;摻雜體系中總態(tài)密度主要是S、Mo態(tài)電子貢獻,摻雜原子相比S、Mo態(tài)電子貢獻很少,且O、N、Si態(tài)電子貢獻程度依次降低。

摘要： High valence state species are significant in the energy-relevant electrochemical oxidation reactions.Herein,the high active state of Ni^(3+)formation induced by Mo^(6+)and their efficient synergism in NiS_(2)-MoS_(2)hetero-nanorods powder catalyst with the rough layered structure are demonstrated,as proof of concept,for the urea-assisted water electrolysis.This catalyst can be derived from the sulfidation of NiMoO_(4) nanorods that can realize individual metal sulfides sufficiently mixing at a domain size in the nanoscale which creates lots of active sites and nanointerfaces.The high valence state of Mo^(6+)and Ni^(3+)formation and increased conductive phase of 1 T MoS_(2)in the hetero-nanorods compared to the counterpart pure phases are revealed by spectral study and microscopic analysis;high electrochemical surface area and active site exposure are found due to the nano-interface formation and layered rough nanosheets over the surface of nanorods.They show much higher catalytic performance than their pure phases for urea oxidation,including high catalytic activity,stability,charge transfer ability and catalytic kinetics resulting from more active Ni^(3+)species formation and electronic synergism of high valence metals.Transformation of 1 T MoS_(2)to Mo^(6+)and increased amount of Mo^(6+)and Ni^(3+)after stability test indicate their involvement and synergism for the catalysis reaction.The current work offers a novel understanding of the synergistic effect based on the high valence state synergism for heterogeneous catalysts in electrocatalysis.

摘要： 為了探究酸性溶液對含MoS_(2)/無水CaCl_(2)潤滑脂添加劑的軸承性能的影響,依據(jù)電機軸承運轉(zhuǎn)機理和失效特征進行了電機軸承運轉(zhuǎn)試驗,選用質(zhì)量分數(shù)為35%的硝酸、鹽酸分別與MoS_(2)、無水CaCl_(2)兩種潤滑脂按照一定的配比進行混合,再將混合物添加到電機軸承中運行一定時間,計算軸承溫度升高值與潤滑脂損失量,考察酸的類型、酸與潤滑脂的配比對電機軸承性能的影響,評價兩種潤滑脂添加劑的耐酸腐蝕性能,為軸承潤滑脂添加劑的選擇提供技術(shù)參考。